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Sun ONE Messaging Server 6.0 Administrator's Guide

Chapter 17
Logging and Log Analysis

Messaging Server can create log files that record events related to its administration, to communications using any of the protocols (SMTP, POP, IMAP, and HTTP) that the server supports, and to other processes employed by the server. By examining the log files, you can monitor many aspects of the server’s operation.

Because the MTA uses a separate logging facility than the other services, you cannot use Console to configure logging services and view logs. Instead, you configure MTA logging by specifying information in configuration files. Consequently this chapter is divided into three parts. The first part describes general introductory information; the second part describes logging for the message store and administration services; the third part describes logging for the MTA service.

"PART 1: Introduction"

"PART 2: Service Logs (Message Store, Administration Server, and MTA)"

"PART 3: Service Logs (MTA)"


PART 1: Introduction

You can customize the policies for creating and managing the Messaging Server log files. This chapter describes the types and structure of log files, and discusses how to administer and how to view the log files. It consists of the following sections:

Logged Services

Messaging Server creates a separate set of log files for each of the major protocols, or services, it supports. These are located in msg_svr_base/data/log. You can customize and view each type of log file individually. Table 17-1 lists the services that can be logged, and describes the log files for each service.

Table 17-1  Logged Services

Service

Log-file description

Admin

Contains logged events related to communication between Console and Messaging Server (mostly through several CGI processes), by way of its Administration Server

SMTP

Contains logged events related to SMTP activity of this server

IMAP

Contains logged events related to IMAP4 activity of this server

POP

Contains logged events related to POP3 activity of this server

HTTP

Contains logged events related to HTTP activity of this server

Default

Contains logged events related to other activity of this server, such as command-line utilities and other processes

Analyzing Logs with Third-Party Tools

For log analyses and report generation beyond the capabilities of Messaging Server, you need to use other tools. You can manipulate log files on your own with text editors or standard system tools.

With a scriptable text editor supporting regular-expression parsing, you can potentially search for and extract log entries based on any of the criteria discussed in this chapter, and possibly sort the results or even generate sums or other statistics.

In UNIX environments you might also be able to modify and use existing report-generation tools that were developed to manipulate UNIX syslog files. If you wish to use a public-domain syslog manipulation tool, remember that you may need to modify it to account for the different date/time format and for the two extra components (facility and logLevel) that appear in Messaging Server log entries but not in syslog entries.


PART 2: Service Logs (Message Store, Administration Server, and MTA)

This section describes logging for the following services: POP, IMAP, HTTP, MTA, Admin, and Default (see Table 17-1).

For these services, you can use Console to specify log settings and to view logs. The settings you specify affect which and how many events are logged. You can use those settings and other characteristics to refine searches for logged events when you are analyzing log files. For additional information on service logs for the MTA see "PART 3: Service Logs (MTA)".

Part 2 contains the following sections:

Log Characteristics

This section describes the following log characteristics for the message store and administration services: logging levels, categories of logged events, filename conventions for logs, and log-file directories.

Logging Levels

The level, or priority, of logging defines how detailed, or verbose, the logging activity is to be. A higher priority level means less detail; it means that only events of high priority (high severity) are logged. A lower level means greater detail; it means that more events are recorded in the log file.

You can set the logging level separately for each service—POP, IMAP, HTTP, Admin, and Default by setting the logfile.service.loglevel configuration parameter (see "Defining and Setting Logging Options"). You can also use logging levels to filter searches for log events. Table 17-2 describes the available levels. These logging levels are a subset of those defined by the UNIX syslog facility.

Table 17-2  Logging Levels for Store and Administration Services

Level

Description

Critical

The minimum logging detail. An event is written to the log whenever a severe problem or critical condition occurs—such as when the server cannot access a mailbox or a library needed for it to run.

Error

An event is written to the log whenever an error condition occurs—such as when a connection attempt to a client or another server fails.

Warning

An event is written to the log whenever a warning condition occurs—such as when the server cannot understand a communication sent to it by a client.

Notice

An event is written to the log whenever a notice (a normal but significant condition) occurs—such as when a user login fails or when a session closes.

Information

An event is written to the log with every significant action that takes place—such as when a user successfully logs on or off or creates or renames a mailbox.

Debug

The most verbose logging. Useful only for debugging purposes. Events are written to the log at individual steps within each process or task, to pinpoint problems.

When you select a particular logging level, events corresponding to that level and to all higher (less verbose) levels are logged. The default level of logging is Notice.


Note

The more verbose the logging you specify, the more disk space your log files will occupy; for guidelines, see Defining and Setting Logging Options.


Categories of Logged Events

Within each supported service or protocol, Messaging Server further categorizes logged events by the facility, or functional area, in which they occur. Every logged event contains the name of the facility that generated it. These categories aid in filtering events during searches. Table 17-3 lists the categories that Messaging Server recognizes for logging purposes.

Table 17-3  Categories in Which Log Events Occur 

Facility

Description

General

Undifferentiated actions related to this protocol or service

LDAP

Actions related to Messaging Server accessing the LDAP directory database

Network

Actions related to network connections (socket errors fall into this category)

Account

Actions related to user accounts (user logins fall into this category)

Protocol

Protocol-level actions related to protocol-specific commands (errors returned by POP, IMAP, or HTTP functions fall into this category)

Stats

Actions related to the gathering of server statistics

Store

Low-level actions related to accessing the message store (read/write errors fall into this category)

For examples of using categories as filters in log searches, see Searching and Viewing Logs.

Filename Conventions for Message Store and Administration Logs

Log files for the POP, IMAP, HTTP, Admin, and Default service use identical naming conventions. Each log file has a filename of the form:

service.sequenceNum.timeStamp

Table 17-4 lists the message store log filename conventions.

Table 17-4  Filename Conventions for Store and Administration Logs

Component

Definition

service

The service being logged: POP, IMAP, HTTP, Admin, Default.

sequenceNum

An integer that specifies the order of creation of this log file compared to others in the log-file directory. Log files with higher sequence numbers are more recent than those with lower numbers. Sequence numbers do not roll over; they increase monotonically for the life of the server (beginning at server installation).

timeStamp

A large integer that specifies the date and time of file creation. (Its value is expressed in standard UNIX time: the number of seconds since midnight January 1, 1970.)

For example, a log file named imap.63.915107696 would be the 63rd log file created in the directory of IMAP log files, created at 12:34:56 PM on December 31, 1998.

The combination of open-ended sequence numbering with a timestamp gives you more flexibility in rotating, expiring, and selecting files for analyzing. For more specific suggestions, see Defining and Setting Logging Options.

Log-File Directories

Every logged service is assigned a single directory, in which its log files are stored. All IMAP log files are stored together, as are all POP log files, and log files of any other service. You define the location of each directory, and you also define how many log files of what maximum size are permitted to exist in the directory.

Make sure that your storage capacity is sufficient for all your log files. Log data can be voluminous, especially at lower (more verbose) logging levels.

It is important also to define your logging level, log rotation, log expiration, and server-backup policies appropriately so that all of your log-file directories are backed up and none of them become overloaded; otherwise, you may lose information. See "Defining and Setting Logging Options".

Log File Format

All message store and administration service log files created by Messaging Server have identical content formats. Log files are multiline text files, in which each line describes one logged event. All event descriptions, for each of the supported services, have the general format:

dateTime hostName processName[pid]: category logLevel: eventMessage

Table 17-5 lists the log file components. Note that this format of event descriptions is identical to that defined by the UNIX syslog facility, except that the date/time format is different and the format includes two additional components (category and logLevel).

Table 17-5  Store and Administration Log File Components

Component

Definition

dateTime

The date and time at which the event was logged, expressed in dd/mm/yyyy hh:mm:ss format, with a time-zone field expressed as +/-hhmm from GMT. For example:
02/Jan/1999:13:08:21 -0700

hostName

The name of the host machine on which the server is running: for example, showshoe.

Note: If there is more than one instance of Messaging Server on the host, you can use the process ID (pid) to separate logged events of one instance from another.

processName

The name of the process that generated the event: for example, cgi_store.

pid

The process ID of the process that generated the event: for example, 18753.

category

The category that the event belongs to: for example, General (see Table 17-3 on page 545).

logLevel

The level of logging that the event represents: for example, Notice (see Table 17-2 on page 544).

eventMessage

An event-specific explanatory message that may be of any length: for example, Log created (894305624).

Here are three examples of logged events as viewed using Console:

02/May/1998:17:37:32 -0700 showshoe cgi_store[18753]:
General Notice:
  Log created (894155852)

04/May/1998:11:07:44 -0400 xyzmail cgi_service[343]: General Error:
  function=getserverhello|port=2500|error=failed to connect

03/Dec/1998:06:54:32 +0200 SiroePost imapd[232]: Account Notice:
  close [127.0.0.1] [unauthenticated] 1998/12/3 6:54:32
  0:00:00 0 115 0

IMAP and POP event entries may end with three numbers. The example above has
0 115 0. The first number is bytes sent by client, the second number is the bytes sent by the server, and third number is mailboxes selected (always 1 for POP).

When viewing a log file in the Log Viewer window, you can limit the events displayed by searching for any specific component in an event, such as a specific logging level or category, or a specific process ID. For more information, see Searching and Viewing Logs.

The event message of each log entry is in a format specific to the type of event being logged, that is, each service defines what content appears in any of its event messages. Many event messages are simple and self-evident; others are more complex.  

Defining and Setting Logging Options

You can define the message store and administration service logging configurations that best serve your administration needs. This section discusses issues that may help you decide on the best configurations and policies, and it explains how to implement them.

Flexible Logging Architecture

The naming scheme for log files (service.sequenceNum.timeStamp) helps you to design a flexible log-rotation and backup policy. The fact that events for different services are written to different files makes it easier for you to isolate problems quickly. Also, because the sequence number in a filename is ever-increasing and the timestamp is always unique, later log files do not simply overwrite earlier ones after a limited set of sequence numbers is exhausted. Instead, older log files are overwritten or deleted only when the more flexible limits of age, number of files, or total storage are reached.

Messaging Server supports automatic rotation of log files, which simplifies administration and facilitates backups. You are not required to manually retire the current log file and create a new one to hold subsequent logged events. You can back up all but the current log file in a directory at any time, without stopping the server or manually notifying the server to start a new log file.

In setting up your logging policies, you can set options (for each service) that control limits on total log storage, maximum number of log files, individual file size, maximum file age, and rate of log-file rotation.

Planning the Options You Want

Keep in mind that you must set several limits, more than one of which might cause the rotation or deletion of a log file. Whichever limit is reached first is the controlling one. For example, if your maximum log-file size is 3.5 MB, and you specify that a new log be created every day, you may actually get log files created faster than one per day if log data builds up faster than 3.5 MB every 24 hours. Then, if your maximum number of log files is 10 and your maximum age is 8 days, you may never reach the age limit on log files because the faster log rotation may mean that 10 files will have been created in less than 8 days.

The following default values, provided for Messaging Server administration logs, may be a reasonable starting point for planning:

Maximum number of log files in a directory: 10
Maximum log-file size: 2 MB
Total maximum size permitted for all log files: 20 MB
Minimum free disk space permitted: 5 MB
Log rollover time: 1 day
Maximum age before expiration: 7 days
Level of logging: Notice

You can see that this configuration assumes that server-administration log data is predicted to accumulate at about 2 MB per day, backups are weekly, and the total space allotted for storage of admin logs is at least 25 MB. (These settings may be insufficient if the logging level is more verbose.)

For POP, IMAP or HTTP logs, the same values might be a reasonable start. If all services have approximately the same log-storage requirements as the defaults shown here, you might expect to initially plan for about 150 MB of total log-storage capacity. (Note that this is meant only as a general indication of storage requirements; your actual requirements may be significantly different.)

To Set Logging Options

You can set options that control the message store logging configuration by using Console or the command line.

The optimal settings for these options depend on the rate at which log data accumulates. It may take between 4,000 and 10,000 log entries to occupy 1 MB of storage. At the more verbose levels of logging (such as Notice), a moderately busy server may generate hundreds of megabytes of log data per week. Here is one approach you can follow:

Note that you can choose to send log information to the syslog facility instead of to the server-supplied log files. You can send log information to syslog by setting the syslogfacility option as follows:

configutil -o logfile.service.syslogfacility -v value

where service is admin, pop, imap, imta, or http and value is user, mail, daemon, local0 to local7, or none.

If the value is set, Messages are logged to the syslog facility corresponding to the set value and all the other log file service options are ignored. When the option is not set or the value is none, logging uses the Messaging Server log files.

Console     To set logging options using Console:

  1. Open the Messaging Server whose log file options you want to set.
  2. Click the Configuration tab, open the Log Files folder in the left pane, and select the log files of a service (such as IMAP, HTTP, or Admin).
  3. From the “Levels of detail” drop-down list, choose a logging level.
  4. In the “Directory path for log files” field, enter the name of the directory to hold your log files.
  5. In the “File size for each log” field, enter your maximum log-file size.
  6. In the “Create new log every” field, enter a number for the log-rotation schedule.
  7. In the “Number of logs per directory” and the “When a log is older than” fields, enter the maximum number of log files and a maximum age to coordinate with your backup schedule.
  8. In the “When total log size exceeds” field, enter the total storage limit you want.
  9. In the “When free disk space is less than” field, enter the minimum amount of free disk space you want to reserve.

Command Line     To set logging options at the command line, use the configutil command as shown in the following examples.

If your system does not support http message access, that is, web mail, you can disable http logging by setting the following variables. Do not set these variables if your system requires web mail support (for example, Messenger Express).

configutil -o service.http.enable -v no
configutil -o service.http.enablesslport -v no

To set the logging level:

configutil -o logfile.service.loglevel -v level

where service is admin, pop, imap, imta, or http and loglevel is Nolog, Critical, Error, Warning, Notice, Information, or Debug.

To specify a directory path for log files:

configutil -o logfile.service.logdir -v dirpath

To specify a maximum file size for each log:

configutil -o logfile.service.maxlogfilesize -v size

where size specifies a number of bytes.

To specify a log rotation schedule:

configutil -o logfile.service.rollovertime -v number

where number specifies a number of seconds.

To specify a maximum number of log files per directory:

configutil -o logfile.service.maxlogfiles -v number

To specify a storage limit:

configutil -o logfile.service.maxlogsize -v number

where number specifies a number in bytes.

To specify the a minimum amount of free disk space you want to reserve:

configutil -o logfile.service.minfreediskspace -v number

where number specifies a number in bytes.

To specify an age for logs at which they will expire:

configutil -o logfile.service.expirytime -v number

where number specifies a number in seconds.

Searching and Viewing Logs

Console provides a basic interface for viewing message store and administration log data. It allows for selecting individual log files and for performing flexible filtered searches of log entries within those files.

For a given service, log files are listed in chronological order. Once you have chosen a log file to search, you can narrow the search for individual events by specifying search parameters.

Search Parameters

These are the search parameters you can specify for viewing log data:

Note: Searches are case-sensitive.

Examples of combining logging level and facility in viewing logs might include the following:

To Specify a Search and Viewing Results

Follow these steps to search for logged events with specific characteristics belonging to a given service:

  1. In Console, open the Messaging Server whose log files you want to inspect.
  2. Follow either of these steps to display the Log Files Content tab for a given logged service:
    • Click the Tasks tab, then click “View service logs”, where service is the name of the logged service (such as “IMAP service” or “administration”).
    • Click the Configuration tab, then open the Log Files folder in the left pane and select the log files of a service (such as IMAP or Admin). Then click the Content tab in the right pane.
  3. The Content tab for that logged service is displayed.
  4. In the Log filename field, select the log file you want to examine.
  5. Click the View selected log button to open the Log Viewer window.
  6. In the Log Viewer window, specify your desired search parameters (described in the previous section, "Search Parameters").
  7. Click Update to perform the search and display the results in the Log entry field.


PART 3: Service Logs (MTA)

The MTA provides facilities for logging each message as it is enqueued and dequeued. It also provides dispatcher error and debugging output. Part 3 contains the following sections:

You can control logging on a per-channel basis or you can specify that message activity on all channels be logged. In the initial configuration, logging is disabled on all channels.

Enabling logging causes the MTA to write an entry to a mail.log* file each time a message passes through an MTA channel. Such log entries can be useful if you wish to get statistics on how many messages are passing through the MTA (or through particular channels), or when investigating other questions such as whether and when a message was sent or delivered.

If you are only interested in gathering statistics on the number of messages passing through a few particular MTA channels, then you may wish to enable the logging channel keyword on just those MTA channels of main interest. Many sites prefer to enable logging on all MTA channels. In particular, if you are trying to track down problems, the first step in diagnosing some problems is to notice that messages are not going to the channel you expected or intended, and having logging enabled for all channels can help you investigate such problems.


Caution

If logging is enabled, mail.log steadily grows and, if left unchecked, consumes all available disk space. Monitor the size of this file and periodically delete unnecessary contents. You can also delete the entire file as another version will be created as needed.


To Enable MTA Logging

To enable logging for a particular channel, you add the logging keyword to the channel definition in the MTA configuration file, as shown in the following example:

channel-name keyword1 keyword2 logging

In addition, you can also set a number of configuration parameters such as directory path for log files, log levels, an so on. See "PART 2: Service Logs (Message Store, Administration Server, and MTA)".

If you wish to have all of your channels log message activity to the logging file, simply add the logging keyword to your defaults channel (see "Configuring Channel Defaults") of the channel block section of your MTA configuration file. For example:

defaults logging notices 1 2 4 7 copywarnpost copysendpost postheadonly noswitchchannel immnonurgent maxjobs 7 defaulthost siroe.com

l defragment charset7 us-ascii charset8 iso-8859-01
siroe.com

Each message is logged as it is enqueued and dequeued. All log entries are made to msg_svr_base/data/logmail.log_current.

The message return job, which runs every night around midnight, appends any existing mail.log_yesterday to the cumulative log file, mail.log, renames the current mail.log_current file to mail.log_yesterday, and then begins a new mail.log_current file. It also performs the analogous operations for any connection.log* files.

You can send MTA log messages to syslog (UNIX) by setting the LOG_MESSAGES_SYSLOG option to 1. 0 is the default and indicates that syslog (event log) logging is not performed.

To Specify Additional MTA Logging Options

In addition to the basic information always provided when logging is enabled, you can specify that additional, optional information fields be included by setting various LOG_* MTA options in the MTA Option file. For complete details about the Option file, see the Messaging Server Reference Manual.

MTA Log Entry Format

The MTA log file is written as ASCII text. By default, each log file entry contains eight or nine fields as shown in the example below.

19-Jan-1998 19:16:57.64 l tcp_local E 1 adam@sesta.com
 rfc822;marlowe@siroe.com marlowe@siroe.com

The log entry shows:

  1. The date and time the entry was made (example: 19-Jan-1998 19:16:57.64).
  2. The channel name for the source channel (in the example, l).
  3. The channel name for the destination channel (in the example, tcp_local). (For SMTP channels, when LOG_CONNECTION is enabled, a plus, +, indicates inbound to the SMTP server; a minus, -, indicates outbound via the SMTP client.)
  4. The type of entry (E); see Table 17-6.
  5. The size of the message (1). This is expressed in kilobytes by default, although this default can be changed by using the BLOCK_SIZE keyword in the MTA option file.
  6. The envelope From: address (adam@sesta.com). Note that for messages with an empty envelope From: address, such as notification messages, this field will be blank.
  7. The original form of the envelope To: address (marlowe@siroe.com).
  8. The active (current) form of the envelope To: address (marlowe@siroe.com).
  9. The delivery status (SMTP channels only).

Table 17-6 describes the logging entry codes.

Table 17-6  Logging Entry Codes

Entry

Description

D

Successful dequeue

DA

Successful dequeue with SASL (authentication)

DS

Successful dequeue with TLS (security)

DSA

Successful dequeue with TLS and SASL (security and authentication)

E

Enqueue

EA

Successful enqueue with SASL (authentication)

ES

Successful enqueue with TLS (security)

ESA

Successful enqueue with TLS and SASL (security and authentication)

J

Rejection of attempted enqueue (rejection by slave channel program)

Q

Temporary failure to dequeue

R

Recipient address rejected on attempted dequeue (rejection by master channel program), or generation of a failure/bounce message

W

Warning message sent to notify original sender that the message has not been delivered yet, but it is still in the queue being retried.

Z

Some successful recipients, but this recipient was temporarily unsuccessful; the original message file of all recipients was dequeued, and in its place a new message file for this and other unsuccessful recipients will be immediately enqueued

SMTP channels' LOG_CONNECTION + or - entries

C

Connection closed

O

Connection opened

X

Connection rejected

Y

Connection attempt failed before being established

I

ETRN command received

With LOG_CONNECTION, LOG_FILENAME, LOG_MESSAGE_ID, LOG_NOTARY, LOG_PROCESS, and LOG_USERNAME all enabled, the format becomes as shown in the example below. (The sample log entry line has been wrapped for typographic reasons; the actual log entry would appear on one physical line.)

19-Jan-1998 13:13:27.10 HOSTA   2e2d.2.1 tcp_local   l
 E 1 service@siroe.com rfc822;adam@sesta.com
 adam 276 /imta/queue/l/ZZ01IWFY9ELGWM00094D.00
 <01IWFVYLGTS499EC9Y@siroe.com> inetmail
 siroe.com (siroe.com [192.160.253.66])

Where the additional fields, beyond those already discussed above, are:

  1. The name of the node on which the channel process is running (in the example, HOSTA).
  2. The process id (expressed in hexadecimal), followed by a period (dot) character and a count. If this had been a multithreaded channel entry (e.g., a tcp_* channel entry), there would also be a thread id present between the process id and the count. In the example, the process id is 2e2d.2.1.
  3. The NOTARY (delivery receipt request) flags for the message, expressed as an integer (in the example, 276).
  4. The file name in the MTA queue area (in the example, /imta/queue/l/ZZ01IWFY9ELGWM00094D.00).
  5. The message id (in the example, <01IWFVYLGTS499EC9Y@siroe.com>).
  6. The name of the executing process (in the example, inetmail). On UNIX, for dispatcher processes such as the SMTP server, this will usually be inetmail (unless SASL was used).
  7. The connection information (in the example, siroe.com (siroe.com [192.160.253.66]). The connection information consists of the sending system or channel name, such as the name presented by the sending system on the HELO/EHLO line (for incoming SMTP messages), or the enqueuing channel's official host name (for other sorts of channels). In the case of TCP/IP channels, the sending system's “real” name, that is, the symbolic name as reported by a DNS reverse lookup and/or the IP address, can also be reported within parentheses as controlled by the ident* channel keywords; see IDENT Lookups. This sample assumes use of one of these keywords, for instance us of the default identnone keyword, that selects display of both the name found from the DNS and IP address.

Managing the MTA Log Files

The message return job, which runs every night around midnight, appends any existing mail.log_yesterday to the cumulative log file, mail.log, renames the current mail.log_current file to mail.log_yesterday, and then begins a new mail.log_current file. It also performs the analogous operations for any connection.log* files.

The MTA performs automatic rollovers to maintain the current file, but you must manage the cumulative mail.log file by determining policies for tasks such as backing up the file, truncating the file, deleting the file, and so on.

When considering how to manage the log files, note that the MTA periodic return job will execute a site-supplied msg_svr_base/bin/daily_cleanup procedure, if one exists. Thus some sites might choose to supply their own cleanup procedure that, for instance, renames the old mail.log file once a week (or once a month), and so on.

Examples of MTA Message Logging

The exact field format and list of fields logged in the MTA message files will vary according to exactly what logging options you set. This section will show a few examples of interpreting typical sorts of log entries. For a description of additional, optional fields, see To Specify Additional MTA Logging Options.


Note

For typographic reasons, log file entries will be shown folded onto multiple lines—actual log file entries are one line per entry.


When reviewing a log file, keep in mind that on a typical system many messages are being handled at once. Typically, the entries relating to a particular message will be interspersed among entries relating to other messages being processed during that same time. The basic logging information is suitable for gathering a sense of the overall numbers of messages moving through the MTA.

If you wish to correlate particular entries relating to the same message to the same recipient(s), you will probably want to enable LOG_MESSAGE_ID. If you wish to correlate particular messages with particular files in the MTA queue area, or to see from the entries how many times a particular not-yet-successfully-dequeued message has had delivery attempted, you will probably want to enable LOG_FILENAME. For SMTP messages (handled via a TCP/IP channel), if you want to correlate TCP connections to and from remote systems with the messages sent, you will probably want to enable LOG_PROCESS and some level of LOG_CONNECTION.

The example below shows a fairly basic example of the sorts of log entries one might see if a local user sends a message out an outgoing TCP/IP channel, for example, to the Internet. In this example, LOG_CONNECTION is enabled. The lines marked with (1) and (2) are one entry—they would appear on one physical line in an actual log file. Similarly, the lines marked with (3) - (7) are one entry and would appear on one physical line.

Code Example 17-1  Logging: A Local User Sends An Outgoing Message

19-Jan-1998 19:16:57.64 l            tcp_local    E 1 (1)
 adam@sesta.com rfc822;marlowe@siroe.com marlowe@siroe.com (2)

19-Jan-1998 19:17:01.16 tcp_local                  D 1 (3)
 adam@sesta.com rfc822;marlowe@siroe.com marlowe@siroe.com (4)
 dns;thor.siroe.com
 (TCP|206.184.139.12|2788|192.160.253.66|25) (5)
 (THOR.SIROE.COM -- Server ESMTP [iMS V5.0 #8694]) (6)
 smtp;250 2.1.5 marlowe@siroe.com and options OK. (7)

  1. This line shows the date and time of an enqueue (E) from the l channel to the tcp_local channel of a one (1) block message.
  2. This is part of the same physical line of the log file as (1), presented here as a separate line for typographical convenience. It shows the envelope From: address, in this case adam@sesta.com, and the original version and current version of the envelope To: address, in this case marlowe@siroe.com.
  3. This shows the date and time of a dequeue (D) from the tcp_local channel of a one (1) block message—that is, a successful send by the tcp_local channel to some remote SMTP server.
  4. This shows the envelope From: address, the original envelope To: address, and the current form of the envelope To: address.
  5. This shows that the actual system to which the connection was made is named thor.siroe.com in the DNS, that the local sending system has IP address 206.184.139.12 and is sending from port 2788, that the remote destination system has IP address 192.160.253.66 and the connection port on the remote destination system is port 25.
  6. This shows the SMTP banner line of the remote SMTP server.
  7. This shows the SMTP status code returned for this address; 250 is the basic SMTP success code and in addition, this remote SMTP server responds with extended SMTP status codes and some additional text.

Code Example 17-2 shows a logging entry similar to that shown in Code Example 17-3, but with the additional information logged by setting LOG_FILENAME=1 and LOG_MESSAGE_ID=1 showing the filename and message-id; see (1) and (2). The message-id in particular can be used to correlate which entries relate to which message.

Code Example 17-2  Logging: Including Optional Logging Fields

19-Jan-1998 19:16:57.64 l            tcp_local    E 1
 adam@sesta.com rfc822;marlowe@siroe.com marlowe@siroe.com
 /imta/queue/tcp_local/ZZ01ISKLSKLZLI90N15M.00
   <01ISKLSKC2QC90N15M@sesta.com> (1)

19-Jan-1998 19:17:01.16 tcp_local                  D 1
 adam@sesta.com rfc822;marlowe@siroe.com marlowe@siroe.com
 /imta/queue/tcp_local/Z01ISKLSKLZLI90N15M.00
   <01ISKLSKC2QC90N15M@sesta.com> (2)
 dns;thor.siroe.com (TCP|206.184.139.12|2788|192.160.253.66|25)
 (THOR.SIROE.COM -- Server ESMTP [iMS V5.0 #8694])
 smtp;250 2.1.5 marlowe@siroe.com and options OK.

Code Example 17-3 illustrates sending to multiple recipients with LOG_FILENAME=1, LOG_MESSAGE_ID=1, and LOG_CONNECTION=1 enabled. Here user adam@sesta.com has sent to the MTA mailing list test-list@sesta.com, which expanded to bob@sesta.com, carol@varrius.com, and david@varrius.com. Note that the original envelope To: address is test-list@sesta.com for each recipient, though the current envelope To: address is each respective address. Note how the message-id is the same throughout, though two separate files (one for the l channel and one going out the tcp_local channel) are involved.

Code Example 17-3  Logging: Sending to a List

19-Jan-1998 20:01:44.10 l    l            E 1
 adam@sesta.com rfc822;test-list@sesta.com bob
 imta/queue/l/ZZ01ISKND3DE1K90N15M.00
 <01ISKND2H8MS90N15M@sesta.com>

19-Jan-1998 20:01:44.81 l            tcp_local    E 1
 adam@sesta.com rfc822;test-list@sesta.com carol@varrius.com
 imta/queue/tcp_local/ZZ01ISKND2WS1I90N15M.00 
 <01ISKND2H8MS90N15M@sesta.com>

19-Jan-1998 20:01:44.81 l            tcp_local    E 1
 adam@sesta.com rfc822;test-list@sesta.com david@varrius.com
 imta/queue/tcp_local/ZZ01ISKND2WS1I90N15M.00
 <01ISKND2H8MS90N15M@sesta.com>

19-Jan-1998 20:01:50.69 l                         D 1
 adam@sesta.com rfc822;test-list@sesta.com bob
 imta/queue/l/ZZ01ISKND3DE1K90N15M.00
 <01ISKND2H8MS90N15M@sesta.com>

19-Jan-1998 20:01:57.36 tcp_local                  D 1
 adam@sesta.com rfc822;test-list@sesta.com carol@varrius.com
 imta/queue/tcp_local/ZZ01ISKND2WS1I90N15M.00
 <01ISKND2H8MS90N15M@sesta.com>
 dns;gw.varrius.com (TCP|206.184.139.12|2788|192.160.253.66|25)
 (gw.varrius.com -- SMTP Sendmail)
 smtp;250 OK.

19-Jan-1998 20:02:06.14 tcp_local                  D 1
 adam@sesta.com rfc822;test-list@sesta.com david@varrius.com
 imta/queue/tcp_local/ZZ01ISKND2WS1I90N15M.00
 <01ISKND2H8MS90N15M@sesta.com>
 dns;gw.varrius.com (TCP|206.184.139.12|2788|192.160.253.66|25)
 (gw.varrius.com -- SMTP Sendmail)
 smtp;250 OK.

Code Example 17-4 illustrates an attempt to send to a non-existent domain (here very.bogus.com); that is, sending to a domain name that is not noticed as non-existent by the MTA's rewrite rules and that the MTA matches to an outgoing TCP/IP channel. This example assumes the MTA option settings of LOG_FILENAME=1 and LOG_MESSAGE_ID=1.

When the TCP/IP channel runs and checks for the domain name in the DNS, the DNS returns an error that no such name exists. Note the “rejection” entry (R), as seen in (5), with the DNS returning an error that this is not a legal domain name, as seen in (6).

Because the address is rejected after the message has been submitted, the MTA generates a bounce message to the original sender. The MTA enqueues the new rejection message to the original sender (1), and sends a copy to the postmaster (4) before deleting the original outbound message (the R entry shown in (5)).

Notification messages, such as bounce messages, have an empty envelope From: address—as seen, for instance, in (2) and (8)—in which the envelope From: field is shown as an empty space. The initial enqueue of a bounce message generated by the MTA shows the message-id for the new notification message followed by the message-id for the original message (3). (Such information is not always available to the MTA, but when it is available to be logged, it allows correlation of the log entries corresponding to the outbound failed message with the log entries corresponding to the resulting notification message.) Such notification messages are enqueued to the process channel, which in turn enqueues them to an appropriate destination channel (7).

Code Example 17-4  Logging: Sending to a Non-existent Domain

19-JAN-1998 20:49:04 l            tcp_local    E 1
 adam@sesta.com rfc822;user@very.bogus.com user@very.bogus.com
 imta/queue/tcp_local/ZZ01ISKP0S0LVQ94DU0K.00
 <01ISKP0RYMAS94DU0K@SESTA.COM>

19-JAN-1998 20:49:33 tcp_local    process      E 1              (1)
 rfc822;adam@sesta.com adam@sesta.com                           (2)
 imta/queue/process/ZZ01ISKP0S0LVQ94DTZB.00
 <01ISKP22MW8894DTAS@SESTA.COM>,<01ISKP0RYMAS94DU0K@SESTA.COM>   (3)

19-JAN-1998 20:49:33 tcp_local    process      E 1               (4)
 rfc822;postmaster@sesta.com postmaster@sesta.com
 imta/queue/process/ZZ01ISKP0S0LVQ94DTZB.00
 <01ISKP22MW8894DTAS@SESTA.COM>,<01ISKP0RYMAS94DU0K@SESTA.COM>

19-JAN-1998 20:50:07 tcp_local                  R 1              (5)
 adam@sesta.com rfc822;user@very.bogus.com user@very.bogus.com
 imta/queue/tcp_local/ZZ01ISKP0S0LVQ94DU0K.00
 <01ISKP0RYMAS94DU0K@SESTA.COM>
 Illegal host/domain name found                                  (6)

19-JAN-1998 20:50:08 process      l            E 3               (7)
 rfc822;adam@sesta.com adam                                      (8)
 imta/queue/l/ZZ01ISKP23BUQS94DTYL.00
 <01ISKP22MW8894DTAS@SESTA.COM>

19-JAN-1998 20:50:08 process      l            E 3
 rfc822;postmaster@sesta.com postmaster
 imta/queue/l/ZZ01ISKP23BUQS94DTYL.00
 <01ISKP22MW8894DTAS@SESTA.COM>

19-JAN-1998 20:50:12 l                         D 3
 rfc822;adam@sesta.com adam
 imta/queue/l/ZZ01ISKP23BUQS94DTYL.00
 <01ISKP22MW8894DTAS@SESTA.COM>

19-JAN-1998 20:50:12 l                         D 3
 rfc822;postmaster@sesta.com postmaster
 imta/queue/l/ZZ01ISKP23BUQS94DTYL.00
 <01ISKP22MW8894DTAS@SIROE.COM>

Code Example 17-5 illustrates an attempt to send to a bad address on a remote system. This example assumes MTA option settings of LOG_FILENAME=1 and LOG_MESSAGE_ID=1, and channel option settings of LOG_BANNER=1 and LOG_TRANSPORTINFO=1. Note the rejection entry (R), seen in (1). But in contrast to the rejection entry in Code Example 17-4, note that the rejection entry here shows that a connection to a remote system was made, and shows the SMTP error code issued by the remote SMTP server, (2) and (3). The inclusion of the information shown in (2) is due to setting the channel options LOG_BANNER=1 and LOG_TRANSPORTINFO=1.

Code Example 17-5  Logging: Sending to a Non-existent Remote User

20-JAN-1998 13:11:05 l            tcp_local    E 1
 adam@sesta.com rfc822;nonesuch@siroe.com nonesuch@siroe.com
 imta/queue/tcp_local/ZZ01ISLNBB1JOE94DUWH.00
 <01ISLNBAWV3094DUWH@sesta.com>

20-JAN-1998 13:11:08 tcp_local    process      E 1
 rfc822;adam@sesta.com adam@sesta.com
 imta/queue/process/ZZ01ISLNBB1JOE94DSGB.00
 <01ISLNBFKIDS94DUJ8@sesta.com>,<01ISLNBAWV3094DUWH@sesta.com>

20-JAN-1998 13:11:08 tcp_local    process      E 1
 rfc822;postmaster@sesta.com postmaster@sesta.com
 imta/queue/process/ZZ01ISLNBB1JOE94DSGB.00
 <01ISLNBFKIDS94DUJ8@sesta.com>,<01ISLNBAWV3094DUWH@sesta.com>

20-JAN-1998 13:11:11 tcp_local                  R 1      (1)
 adam@sesta.com rfc822;nonesuch@siroe.com nonesuch@siroe.com
 imta/queue/tcp_local/ZZ01ISLNBB1JOE94DUWH.00 
 <01ISLNBAWV3094DUWH@sesta.com>
 dns;thor.siroe.com
 (TCP|206.184.139.12|2788|192.160.253.66|25)             (2)
 (THOR.SIROE.COM -- Server ESMTP [iMS V5.0 #8694])
 smtp; 553 unknown or illegal user: nonesuch@siroe.com   (3)

20-JAN-1998 13:11:12 process      l            E 3
 rfc822;adam@sesta.com adam
 imta/queue/l/ZZ01ISLNBGND1094DQDP.00
 <01ISLNBFKIDS94DUJ8@sesta.com>

20-JAN-1998 13:11:12 process      l            E 3
 rfc822;postmaster@sesta.com postmaster
 imta/queue/l/ZZ01ISLNBGND1094DQDP.00
 <01ISLNBFKIDS94DUJ8@sesta.com>

20-JAN-1998 13:11:13 l                         D 3
 rfc822;adam@sesta.com adam@sesta.com
 imta/queue/l/ZZ01ISLNBGND1094DQDP.00
 <01ISLNBFKIDS94DUJ8@sesta.com>

20-JAN-1998 13:11:13 l                         D 3
 rfc822;postmaster@sesta.com postmaster@sesta.com
 imta/queue/l/ZZ01ISLNBGND1094DQDP.00
 <01ISLNBFKIDS94DUJ8@sesta.com>

Code Example 17-6 illustrates the sort of log file entry resulting when the MTA rejects a remote side’s attempt to submit a message. (This example assumes that no optional LOG_* options are enabled, so only the basic fields are logged in the entry. Note that enabling the LOG_CONNECTION option, in particular, would result in additional informative fields in such J entries.) In this case, the example is for an MTA that has set up SMTP relay blocking (see Configuring SMTP Relay Blocking) with an ORIG_SEND_ACCESS mapping including:

ORIG_SEND_ACCESS

! ...numerous entries omitted...
!
   tcp_local|*|tcp_local|*   $NRelaying$ not$ permitted

and where alan@very.bogus.com is not an internal address. Hence the attempt of the remote user harold@varrius.com to relay through the MTA system to the remote user alan@very.bogus.com is rejected.

Code Example 17-6  Logging: Rejecting a Remote Side's Attempt to Submit a Message

28-May-1998 12:02:23 tcp_local                  J 0         (1)
 harold@varrius.com rfc822; alan@very.bogus.com             (2)
 550 5.7.1 Relaying not permitted: alan@very.bogus.com    (3)

  1. This log shows the date and time the MTA rejects a remote side’s attempt to submit a message. The rejection is indicated by a J record. (Cases where an MTA channel is attempting to send a message which is rejected is indicated by R records, as shown in Code Example 17-4 and Code Example 17-5).
  2. The attempted envelope From: and To: addresses are shown. In this case, no original envelope To: information was available so that field is empty.
  3. The entry includes the SMTP error message the MTA issued to the remote (attempted sender) side.

Code Example 17-7 illustrates the sort of log file entries resulting when a message cannot be delivered upon the first attempt, so the MTA attempts to send the message several times. This example assumes option settings of LOG_FILENAME=1 and LOG_MESSAGE_ID=1.

Code Example 17-7  Logging: Multiple Delivery Attempts

15-Jan-1998 10:31:05.18 tcp_internal   tcp_local   E 3    (1)
 adam@hosta.sesta.com rfc822;user@some.org user@some.org
 imta/queue/tcp_local/ZZ01IS3D2ZP7FQ9UN54R.00 
 <01IRUD7SVA3Q9UN2D4@sesta.com>

15-Jan-1998 10:31:10.37 tcp_local                  Q 3    (2)
 adam@hosta.sesta.com rfc822;user@some.org user@some.org
 imta/queue/tcp_local/ZZ01IS3D2ZP7FQ9UN54R.00             (3)
 <01IRUD7SVA3Q9UN2D4@sesta.com>
 TCP active open: Failed connect()    Error: no route to host (4)

 ...several hours worth of entries...

15-Jan-1998 12:45:39.48 tcp_local                  Q 3     (5)
 adam@hosta.sesta.com rfc822;user@some.org user@some.org
 imta/queue/tcp_local/ZY01IS3D2ZP7FQ9UN54R.00              (6)
 <01IRUD7SVA3Q9UN2D4@sesta.com>
 TCP active open: Failed connect()    Error: no route to host

 ...several hours worth of entries...

15-Jan-1998 16:45:24.72 tcp_local                  Q 3
 adam@hosta.sesta.com rfc822;user@some.org user@some.org
 imta/queue/tcp_local/ZX01IS67NY4RRK9UN7GP.00                (7)
 <01IRUD7SVA3Q9UN2D4@sesta.com>
 TCP active open: Failed connect() Error: connection refused (8)

 ...several hours worth of entries...

15-Jan-1998 20:45:51.55 tcp_local                  D 3       (9)
 adam@hosta.sesta.com rfc822;user@some.org user@some.org
 imta/queue/tcp_local/ZX01IS67NY4RRK9UN7GP.00
 <01IRUD7SVA3Q9UN2D4@sesta.com>
 dns;host.some.org (TCP|206.184.139.12|2788|192.1.1.1|25)
 (All set, fire away)
 smtp; 250 Ok

  1. The message comes in the tcp_internal channel—perhaps from a POP or IMAP client, or perhaps from another host within the organization using the MTA as an SMTP relay; the MTA enqueues it to the outgoing tcp_local channel.
  2. The first delivery attempt fails, as indicated by the Q entry.
  3. That this is a first delivery attempt can be seen from the ZZ* filename.
  4. This delivery attempt failed when the TCP/IP package could not find a route to the remote side. As opposed to Code Example 17-4, the DNS did not object to the destination domain name, some.org; rather, the “no route to host” error indicates that there is some network problem between the sending and receiving side.
  5. The next time the MTA periodic job runs it reattempts delivery, again unsuccessfully.
  6. The file name is now ZY*, indicating that this is a second attempt.
  7. The file name is ZX* for this third unsuccessful attempt.
  8. The next time the periodic job reattempts delivery the delivery fails, though this time the TCP/IP package is not complaining that it cannot get through to the remote SMTP server, but rather the remote SMTP server is not accepting connections. (Perhaps the remote side fixed their network problem, but has not yet brought their SMTP server back up—or their SMTP server is swamped handling other messages and hence was not accepting connections at the moment the MTA tried to connect.)
  9. Finally the message is dequeued.

Code Example 17-8 illustrates the case of a message routed through the conversion channel. The site is assumed to have a CONVERSIONS mapping table such as:

CONVERSIONS

  IN-CHAN=tcp_local;OUT-CHAN=l;CONVERT   Yes

This example assumes option settings of LOG_FILENAME=1 and LOG_MESSAGE_ID=1.

Code Example 17-8  Logging: Incoming SMTP Message Routed Through the Conversion Channel

04-Feb-1998 00:06:26.72 tcp_local    conversion   E 9 (1)
 amy@siroe.edu rfc822;bert@sesta.com bert@sesta.com
 imta/queue/conversion/ZZ01IT5UAMZ4QW98518O.00
 <01IT5UALL14498518O@siroe.edu>

04-Feb-1998 00:06:29.06 conversion   l            E 9 (2)
 amy@siroe.edu rfc822;bert@sesta.com bert
 imta/queue/l/ZZ01IT5UAOXLDW98509E.00  <01IT5STUMUFO984Z8L@siroe.edu>

04-Feb-1998 00:06:29.31 conversion                D 9 (3)
 amy@siroe.edu rfc822;bert@sesta.com bert
 imta/queue/conversion/ZZ01IT5UAMZ4QW98518O.00
 <01IT5UALL14498518O@siroe.edu>

04-Feb-1998 00:06:32.62 l                         D 9 (4)
 amy@siroe.edu rfc822;bert@siroe.com bert
 imta/queue/l/ZZ01IT5UAOXLDW98509E.00
 <01IT5STUMUFO984Z8L@siroe.edu>

  1. The message from external user amy@siroe.edu comes in addressed to the l channel recipient bert@sesta.com. The CONVERSIONS mapping entry, however, causes the message to be initially enqueued to the conversion channel (rather than directly to the l channel).
  2. The conversion channel runs and enqueues the message to the l channel.
  3. Then the conversion channel can dequeue the message (delete the old message file).
  4. And finally the l channel dequeues (delivers) the message.

Code Example 17-9 illustrates log output for an outgoing message when connection logging is enabled, via LOG_CONNECTION=3. LOG_PROCESS=1, LOG_MESSAGE_ID=1 and LOG_FILENAME=1 are also assumed in this example. The example shows the case of user adam@sesta.com sending the same message (note that the message ID is the same for each message copy) to three recipients, bobby@hosta.sesta.com, carl@hosta.sesta.com, and dave@hostb.sesta.com. This example assumes that the message is going out a tcp_local channel marked (as such channels usually are) with the single_sys channel keyword. Therefore, a separate message file on disk will be created for each set of recipients to a separate host name, as seen in (1), (2), and (3), where the bobby@hosta.sesta.com and carl@hosta.sesta.com recipients are stored in the same message file, but the dave@hostb.sesta.com recipient is stored in a different message file.

Code Example 17-9  Logging: Outbound Connection Logging

19-Feb-1998 10:52:05.41 1e488.0 l            tcp_local    E 1

 adam@sesta.com rfc822;bobby@hosta.sesta.com bobby@hosta.sesta.com

 imta/queue/tcp_local/ZZ01ITRF7BO388000FCN.00                (1)

  <01ITRF7BDHS6000FCN@SESTA.COM>

19-Feb-1998 10:52:05.41 1e488.0 l            tcp_local    E 1

 adam@sesta.com rfc822;carl@hosta.sesta.com carl@hosta.sesta.com

 imta/queue/tcp_local/ZZ01ITRF7BO388000FCN.00                (2)

  <01ITRF7BDHS6000FCN@SESTA.COM>

19-Feb-1998 10:52:05.74 1e488.1 l            tcp_local    E 1

 adam@sesta.com rfc822;dave@hostb.sesta.com dave@hostb.sesta.com

 imta/queue/tcp_local/ZZ01ITRF7C11FU000FCN.00                 (3)

  <01ITRF7BDHS6000FCN@SESTA.COM>

19-Feb-1998 10:52:10.79 1f625.2.0 tcp_local    -            O (4)

 TCP|206.184.139.12|5900|206.184.139.66|25

 SMTP/hostb.sesta.com/mailhub.sesta.com                       (5)

19-Feb-1998 10:52:10.87 1f625.3.0 tcp_local    -            O (6)

 TCP|206.184.139.12|5901|206.184.139.70|25

 SMTP/hosta.sesta.com/hosta.sesta.com                         (7)

19-Feb-1998 10:52:12.28 1f625.3.1 tcp_local                  D 1

 adam@sesta.com rfc822;bobby@hosta.sesta.com bobby@hosta.sesta.com

 imta/queue/tcp_local/ZZ01ITRF7BO388000FCN.00

  <01ITRF7BDHS6000FCN@SESTA.COM>

 hosta.sesta.com dns;hosta.sesta.com                          (8)

 (TCP|206.184.139.12|5901|206.184.139.70|25)

 (hosta.sesta.com -- Server ESMTP [iMS V5.0 #8790])

 (TCP|206.184.139.12|5901|206.184.139.70|25)

 smtp;250 2.1.5 bobby@hosta.sesta.com and options OK.

19-Feb-1998 10:52:12.28 1f625.3.1 tcp_local                  D 1

 adam@sesta.com rfc822;carl@hosta.sesta.com carl@hosta.sesta.com

 imta/queue/tcp_local/ZZ01ITRF7BO388000FCN.00

  <01ITRF7BDHS6000FCN@SESTA.COM>

 hosta.sesta.com dns;hosta.sesta.com

 (TCP|206.184.139.12|5901|206.184.139.70|25)

 (hosta.sesta.com -- Server ESMTP [iMS V5.0 #8790])

 (TCP|206.184.139.12|5901|206.184.139.70|25)

 smtp;250 2.1.5 carl@hosta.sesta.com and options OK.

19-Feb-1998 10:52:12.40 1f625.3.2 tcp_local      -            C (9)

 TCP|206.184.139.12|5901|206.184.139.70|25

 SMTP/hosta.sesta.com/hosta.sesta.com

19-Feb-1998 10:52:13.01 1f625.2.1 tcp_local                  D 1

 adam@sesta.com rfc822;dave@hostb.sesta.com dave@hostb.sesta.com

 imta/queue/tcp_local/ZZ01ITRF7C11FU000FCN.00

  <01ITRF7BDHS6000FCN@SESTA.COM>

 mailhub.sesta.com dns;mailhub.sesta.com

 (TCP|206.184.139.12|5900|206.184.139.66|25)

 (MAILHUB.SESTA.COM -- Server ESMTP [iMS V5.0 #8694])

 (TCP|206.184.139.12|5900|206.184.139.66|25)

 smtp;250 2.1.5 dave@hostb.sesta.com and options OK.

19-Feb-1998 10:52:13.05 1f625.2.2 tcp_local      -            C (10)

 TCP|206.184.139.12|5900|206.184.139.66|25

 SMTP/hostb.sesta.com/mailhub.sesta.com

  1. The message is enqueued to the first recipient...
  2. ....and to the second recipient...
  3. ....and to the third recipient.
  4. Having LOG_CONNECTION=3 set causes the MTA to write this entry. The minus, -, indicates that this entry refers to an outgoing connection. The O means that this entry corresponds to the opening of the connection. Also note that the process id here is the same, 1f625, since the same process is used for the multithreaded TCP/IP channel for these separate connection opens, though this open is being performed by thread 2 vs. thread 3.
  5. As there are two separate remote systems to which to connect, the multithreaded SMTP client in separate threads opens up a connection to each—the first in this entry, and the second shown in 7. This part of the entry shows the sending and destination IP numbers and port numbers, and shows both the initial host name, and the host name found by doing a DNS lookup. In the SMTP/initial-host/dns-host clauses, note the display of both the initial host name, and that used after performing a DNS MX record lookup on the initial host name: mailhub.sesta.com is apparently an MX server for hostb.sesta.com.
  6. The multithreaded SMTP client opens up a connection to the second system in a separate thread (though the same process).
  7. As there are two separate remote systems to which to connect, the multithreaded SMTP client in separate threads opens up a connection to each—the second in this entry, and the first shown above in 5. This part of the entry shows the sending and destination IP numbers and port numbers, and shows both the initial host name, and the host name found by doing a DNS lookup. In this example, the system hosta.sesta.com apparently receives mail directly itself.
  8. Besides resulting in specific connection entries, LOG_CONNECTION=3 also causes inclusion of connection related information in the regular message entries, as seen here for instance.
  9. Having LOG_CONNECTION=3 causes the MTA to write this entry. After any messages are dequeued, (the bobby and carl messages in this example), the connection is closed, as indicated by the C in this entry.
  10. Having LOG_CONNECTION=3 causes the MTA to write this entry. After any messages are dequeued, (the dave message in this example), the connection is closed, as indicated by the C in this entry.

Code Example 17-10 illustrates log output for an incoming SMTP message when connection logging is enabled, via LOG_CONNECTION=3.

Code Example 17-10  Logging: Inbound Connection Logging

19-Feb-1998 17:02:08.70 tcp_local    +            O   (1)
 TCP|206.184.139.12|25|192.160.253.66|1244 SMTP       (2)

19-Feb-1998 17:02:26.65 tcp_local    l             E 1
 service@siroe.com rfc822;adam@sesta.com adam
 THOR.SIROE.COM (THOR.SIROE.COM [192.160.253.66])      (3)

19-Feb-1998 17:02:27.05 tcp_local    +             C   (4)
 TCP|206.184.139.12|25|192.160.253.66|1244 SMTP

19-Feb-1998 17:02:31.73 l                          D 1
 service@siroe.com rfc822;adam@sesta.com adam

  1. The remote system opens a connection. The O character indicates that this entry regards the opening of a connection; the + character indicates that this entry regards an incoming connection.
  2. The IP numbers and ports for the connection are shown. In this entry, the receiving system (the system making the log file entry) has IP address 206.184.139.12 and the connection is being made to port 25; the sending system has IP address 192.160.253.66 and is sending from port 1244.
  3. In the entry for the enqueue of the message from the incoming TCP/IP channel (tcp_local) to the l channel recipient, note that information beyond the default is included since LOG_CONNECTION=3 is enabled. Specifically, the name that the sending system claimed on its HELO or EHLO line, the sending system’s name as found by a DNS reverse lookup on the connection IP number, and the sending system’s IP address are all logged; see Chapter 10, "Configuring Channel Definitions" for a discussion of channel keywords affecting this behavior.
  4. The inbound connection is closed. The C character indicates that this entry regards the closing of a connection; the + character indicates that this entry regards an incoming connection.

Dispatcher Debugging and Log Files

Dispatcher error and debugging output (if enabled) are written to the file dispatcher.log in the MTA log directory.

Debugging output may be enabled using the option DEBUG in the Dispatcher configuration file, or on a per-process level, using the IMTA_DISPATCHER_DEBUG environment variable (UNIX).

The DEBUG option or IMTA_DISPATCHER_DEBUG environment variable (UNIX) defines a 32-bit debug mask in hexadecimal. Enabling all debugging is done by setting the option to -1, or by defining the logical or environment variable system-wide to the value FFFFFFFF. The actual meaning of each bit is described in Table 17-7.

Table 17-7  Dispatcher Debugging Bits 

Bit

 

Hexadecimal
value

Decimal
value

Usage

 

0

x 00001

1

Basic Service Dispatcher main module debugging.

1

x 00002

2

Extra Service Dispatcher main module debugging.

2

x 00004

4

Service Dispatcher configuration file logging.

3

x 00008

8

Basic Service Dispatcher miscellaneous debugging.

4

x 00010

16

Basic service debugging.

5

x 00020

32

Extra service debugging.

6

x 00040

64

Process related service debugging.

7

x 00080

128

Not used.

8

x 00100

256

Basic Service Dispatcher and process communication debugging.

9

x 00200

512

Extra Service Dispatcher and process communication debugging.

10

x 00400

1024

Packet level communication debugging.

11

x 00800

2048

Not used.

12

x 01000

4096

Basic Worker Process debugging.

13

x 02000

8192

Extra Worker Process debugging.

14

x 04000

16384

Additional Worker Process debugging, particularly connection hand-offs.

15

x 08000

32768

Not used.

16

x 10000

65536

Basic Worker Process to Service Dispatcher I/O debugging.

17

x 20000

131072

Extra Worker Process to Service Dispatcher I/O debugging.

20

x 100000

1048576

Basic statistics debugging.

21

x 200000

2097152

Extra statistics debugging.

24

x 1000000

16777216

Log PORT_ACCESS denials to the dispatcher.log file.

System Parameters on Solaris

The system’s heap size (datasize) must be enough to accommodate the Dispatcher’s thread stack usage. For each Dispatcher service compute STACKSIZE*MAX_CONNS, and then add up the values computed for each service. The system’s heap size needs to be at least twice this number.

The Dispatcher services offered in the Dispatcher configuration file affects requirements for various system parameters.

To display the heap size (that is, default datasize), use the csh command:

# limit

or the ksh command

# ulimit -a

or the utility

# sysdef



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