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Oracle® Database Administrator's Guide
11g Release 2 (11.2)

E25494-05
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30 Administering Oracle Scheduler

In this chapter:

Note:

This chapter describes how to use the DBMS_SCHEDULER package to administer Oracle Scheduler. You can accomplish many of the same tasks using Oracle Enterprise Manager.

See Oracle Database PL/SQL Packages and Types Reference for DBMS_SCHEDULER information and the Oracle Enterprise Manager online help for information on Oracle Scheduler pages.

Configuring Oracle Scheduler

This section contains:

Setting Oracle Scheduler Privileges

You must have the SCHEDULER_ADMIN role to perform all Oracle Scheduler administration tasks. Typically, database administrators already have this role with the ADMIN option as part of the DBA role. For example, users SYS and SYSTEM are granted the DBA role. You can grant this role to another administrator by issuing the following statement:

GRANT SCHEDULER_ADMIN TO username;

Because the SCHEDULER_ADMIN role is a powerful role allowing a grantee to execute code as any user, you should consider granting individual Scheduler system privileges instead. Object and system privileges are granted using regular SQL grant syntax. An example is if the database administrator issues the following statement:

GRANT CREATE JOB TO scott;

After this statement is executed, scott can create jobs, schedules, programs, file watchers, and credentials in his schema. Another example is if the database administrator issues the following statement:

GRANT MANAGE SCHEDULER TO adam;

After this statement is executed, adam can create, alter, or drop windows, job classes, or window groups. He will also be able to set and retrieve Scheduler attributes and purge Scheduler logs.

Setting Chain Privileges

Scheduler chains use underlying Oracle Streams Rules Engine objects along with their associated privileges. To create a chain in their own schema, users must have the CREATE JOB privilege in addition to the Rules Engine privileges required to create rules, rule sets, and evaluation contexts in their own schema. These can be granted by issuing the following statement:

GRANT CREATE RULE, CREATE RULE SET, CREATE EVALUATION CONTEXT TO user;

To create a chain in a different schema, users must have the CREATE ANY JOB privilege in addition to the privileges required to create rules, rule sets, and evaluation contexts in schemas other than their own. These can be granted by issuing the following statement:

GRANT CREATE ANY RULE, CREATE ANY RULE SET, 
   CREATE ANY EVALUATION CONTEXT TO user;

Altering or dropping chains in schemas other than the users's schema require corresponding system Rules Engine privileges for rules, rule sets, and evaluation contexts.

See Also:

"Chain Tasks and Their Procedures" for more information regarding chain privileges.

Setting Scheduler Preferences

There are several systemwide Scheduler preferences that you can set. You set these preferences by setting Scheduler attributes with the SET_SCHEDULER_ATTRIBUTE procedure. Setting these attributes requires the MANAGE SCHEDULER privilege. The attributes are:

  • default_timezone

    It is very important that you set this attribute. Repeating jobs and windows that use the calendaring syntax need to know which time zone to use for their repeat intervals. See "Using the Scheduler Calendaring Syntax". They normally retrieve the time zone from start_date, but if no start_date is provided (which is not uncommon), they retrieve the time zone from the default_timezone Scheduler attribute.

    The Scheduler derives the value of default_timezone from the operating system environment. If the Scheduler can find no compatible value from the operating system, it sets default_timezone to NULL.

    It is crucial that you verify that default_timezone is set properly, and if not, that you set it. To verify it, run this query:

    SELECT DBMS_SCHEDULER.STIME FROM DUAL;
     
    STIME
    ---------------------------------------------------------------------------
    14-OCT-04 02.56.03.206273000 PM US/PACIFIC
    

    To ensure that daylight savings adjustments are followed, it is recommended that you set default_timezone to a region name instead of an absolute time zone offset like '-8:00'. For example, if your database resides in Miami, Florida, USA, issue the following statement:

    DBMS_SCHEDULER.SET_SCHEDULER_ATTRIBUTE('default_timezone','US/Eastern');
    

    Similarly, if your database resides in Paris, you would set this attribute to 'Europe/Warsaw'. To see a list of valid region names, run this query:

    SELECT DISTINCT TZNAME FROM V$TIMEZONE_NAMES;
    

    If you do not properly set default_timezone, the default time zone for repeating jobs and windows will be the absolute offset retrieved from SYSTIMESTAMP (the time zone of the operating system environment of the database), which means that repeating jobs and windows that do not have their start_date set will not follow daylight savings adjustments.

  • email_server

    This attribute specifies an SMTP server address that the Scheduler uses to send e-mail notifications for job state events. It takes the following format:

    host[:port]
    

    where:

    • host is the host name or IP address of the SMTP server.

    • port is the TCP port on which the SMTP server listens. If not specified, the default port of 25 is used.

    If this attribute is not specified, set to NULL, or set to an invalid SMTP server address, the Scheduler cannot send job state e-mail notifications.

  • email_sender

    This attribute specifies the default e-mail address of the sender for job state e-mail notifications. It must be a valid e-mail address. If this attribute is not set or set to NULL, then job state e-mail notifications that do not specify a sender address do not have a FROM address in the e-mail header.

  • email_server_credential

    This attribute specifies the schema and name of an existing credential object. The default is NULL.

    When an e-mail notification goes out, the Scheduler determines if the email_server_credential points to a valid credential object that SYS has execute object privileges on. If the SMTP server specified in the email_server attribute requires authentication, then the Scheduler uses the user name and password stored in the specified credential object to authenticate with the e-mail server.

    If the email_server_credential is specified, then the email_server attribute must specify an SMTP server that requires authentication.

    If the email_server_credential is not specified, then the Scheduler supports sending notification e-mails through an SMTP server for which authentication is not configured.

    Note:

    This functionality is available with Oracle Database 11g release 2 (11.2.0.2).
  • email_server_encryption

    This attribute indicates whether encryption is enabled for this SMTP server connection, and if so, at what point encryption starts, and with which protocol.

    Values for email_server_encryption are:

    NONE: The default, indicates no encryption.

    SSL_TLS: Indicates that either SSL or TLS are used, from the beginning of the connection. The two sides determine which protocol is most secure. This is the most common setting for this parameter.

    STARTTLS: Indicates that the connection starts in an unencrypted state, but then the command STARTTLS directs the e-mail server to start encryption using TLS.

    Note:

    This functionality is available with Oracle Database 11g release 2 (11.2.0.2).
  • event_expiry_time

    This attribute enables you to set the time in seconds before a job state event generated by the Scheduler expires (is automatically purged from the Scheduler event queue). If NULL, job state events expire after 24 hours.

  • log_history

    This attribute controls the number of days that log entries for both the job log and the window log are retained. It helps prevent logs from growing indiscriminately. The range of valid values is 0 through 1000000. If set to 0, no history is kept. Default value is 30. You can override this value at the job class level by setting a value for the log_history attribute of the job class.

See Oracle Database PL/SQL Packages and Types Reference for the syntax for the SET_SCHEDULER_ATTRIBUTE procedure.

Using the Oracle Scheduler Agent to Run Remote Jobs

Using the Oracle Scheduler agent, the Scheduler can schedule and run two types of remote jobs:

  • Remote database jobs: Remote database jobs must be run through an Oracle Scheduler agent. Oracle recommends that an agent be installed on the same host as the remote database.

    If you intend to run remote database jobs, the Scheduler agent must be release 11.2 or later.

  • Remote external jobs: Remote external jobs run on the same host that the Scheduler agent is installed on.

    If you intend to run only remote external jobs, release 11.1 of the Scheduler agent is sufficient.

You must install Scheduler agents on all hosts that remote external jobs will run on. You should install Scheduler agents on all hosts running remote databases that remote database jobs will be run on.

Each database that runs remote jobs requires an initial setup to enable secure communications between databases and remote Scheduler agents, as described in "Setting up Databases for Remote Jobs".

Enabling remote jobs involves the following steps:

  1. Enabling and Disabling Databases for Remote Jobs

  2. Installing and Configuring the Scheduler Agent on a Remote Host

  3. Performing Tasks with the Scheduler Agent

See Also:

Enabling and Disabling Databases for Remote Jobs

This section covers these topics:

Setting up Databases for Remote Jobs

Before a database can run jobs using a remote Scheduler agent, the database must be properly configured, and the agent must be registered with the database. This section describes the configuration, including the required agent registration password in the database. You will later register the database, as shown in "Registering Scheduler Agents with Databases".

You can limit the number of Scheduler agents that can register, and you can set the password to expire after a specified duration.

Complete the following steps once for each database that creates and runs remote jobs.

To set up a database to create and run remote jobs:

  1. Ensure that shared server is enabled.

    See "Enabling Shared Server".

  2. Using SQL*Plus, connect to the database as the SYS user.

  3. Enter the following command to verify that the XML DB option is installed:

    SQL> DESC RESOURCE_VIEW
    

    If XML DB is not installed, this command returns an "object does not exist" error.

    Note:

    If XML DB is not installed, you must install it before continuing.
  4. Enable HTTP connections to the database as follows:

    1. Determine whether or not the Oracle XML DBM HTTP Server is enabled:

      Issue the following command:

      SQL> SELECT DBMS_XDB.GETHTTPPORT() FROM DUAL;
      

      If this statement returns 0, Oracle XML DBM HTTP Server is disabled.

    2. Enable Oracle XML DB HTTP Server on a nonzero port by logging in as SYS and issuing the following commands:

      SQL> EXEC DBMS_XDB.SETHTTPPORT (port);
      SQL> COMMIT;
      

      where port is the TCP port number on which you want the database to listen for HTTP connections.

      port must be an integer between 1 and 65536, and for UNIX and Linux must be greater than 1023. Choose a port number that is not already in use.

      Note:

      This enables HTTP connections on all instances of an Oracle Real Application Clusters database.
  5. Run the script prvtrsch.plb with following command:

    SQL> @?/rdbms/admin/prvtrsch.plb
    
  6. Set a registration password for the Scheduler agents using the SET_AGENT_REGISTRATION_PASS procedure.

    The following example sets the agent registration password to mypassword.

    BEGIN
      DBMS_SCHEDULER.SET_AGENT_REGISTRATION_PASS('mypassword');
    END;
    /
    

    Note:

    You must have the MANAGE SCHEDULER privilege to set an agent registration password. See Oracle Database PL/SQL Packages and Types Reference for more information on the SET_AGENT_REGISTRATION_PASS procedure.

    You will do the actual registration further on, in "Registering Scheduler Agents with Databases".

Disabling Remote Jobs

You can disable remote jobs on a database by dropping the REMOTE_SCHEDULER_AGENT user.

To disable remote jobs:

  • Submit the following SQL statement:

    DROP USER REMOTE_SCHEDULER_AGENT CASCADE;
    

Registration of new scheduler agents and execution of remote jobs is disabled until you run prvtrsch.plb again.

Installing and Configuring the Scheduler Agent on a Remote Host

Before you can run remote jobs on a particular host, you must install and configure the Scheduler agent, described in this section, and then register and start the Scheduler agent on the host, described in "Performing Tasks with the Scheduler Agent". The Scheduler agent must also be installed in its own Oracle home.

To install and configure the Scheduler agent on a remote host:

  1. Download or retrieve the Scheduler agent software, which is available on the Oracle Database Client media included in the Database Media Pack, and online at:

    http://www.oracle.com/technology/software/products/database

  2. Ensure that you have first properly set up any database on which you want to register the agent.

    See "Enabling and Disabling Databases for Remote Jobs" for instructions.

  3. Log in to the host you want to install the Scheduler agent on. This host runs remote jobs.

    • For Windows, log in as an administrator.

    • For UNIX and Linux, log in as the user that you want the Scheduler agent to run as. This user requires no special privileges.

  4. Run the Oracle Universal Installer (OUI) from the installation media for Oracle Database Client.

    • For Windows, run setup.exe.

    • For UNIX and Linux, use the following command:

      /directory_path/runInstaller
      

    where directory_path is the path to the Oracle Database Client installation media.

  5. On the Select Installation Type page, select Custom, and then click Next.

  6. On the Select Product Languages page, select the desired languages, and click Next.

  7. On the Specify Install Location page, enter the path for a new Oracle home for the agent, and then click Next.

  8. On the Available Product Components page, select Oracle Scheduler Agent, and click Next.

  9. On the Oracle Database Scheduler Agent page:

    1. In the Scheduler Agent Hostname field, enter the host name of the computer that the Scheduler agent is installed on.

    2. In the Scheduler Agent Port Number field, enter the TCP port number that the Scheduler agent is to listen on for connections, or accept the default, and then click Next.

      Choose an integer between 1 and 65535. On UNIX and Linux, the number must be greater than 1023. Ensure that the port number is not already in use.

      OUI performs a series of prerequisite checks. If any of the prerequisite checks fail, resolve the problems, and then click Next.

  10. On the Summary page, click Finish.

  11. (UNIX and Linux only) When OUI prompts you to run the script root.sh, enter the following command as the root user:

    script_path/root.sh
    

    The script is located in the directory that you chose for agent installation.

    When the script completes, click OK in the Execute Configuration Scripts dialog box.

  12. Click Close to exit OUI when installation is complete.

  13. Use a text editor to review the agent configuration parameter file schagent.conf, which is located in the Scheduler agent home directory, and verify the port number in the PORT= directive.

  14. Ensure that any firewall software on the remote host or any other firewall that protects that host has an exception to accommodate the Scheduler agent.

Performing Tasks with the Scheduler Agent

The Scheduler agent is a standalone program that enables you to schedule and run external and database jobs on remote hosts. You start and stop the Scheduler agent using the schagent utility on UNIX and Linux, and the OracleSchedulerExecutionAgent service on Windows.

This section covers these topics:

About the schagent utility

The executable utility schagent performs certain tasks for the agent on Windows, UNIX and Linux, as indicated by the options in Table 30-1.

Use schagent with the appropriate syntax and options as follows:

For example:

UNIX and Linux: AGENT_HOME/bin/schagent -status

Windows: AGENT_HOME/bin/schagent.exe -status

Table 30-1 schagent options

Option Description

-start

Starts the Scheduler Agent.

UNIX and Linux only

-stop

Prompts the Scheduler agent to stop all the currently running jobs and then stop execution gracefully.

UNIX and Linux only

-abort

Stops the Scheduler agent forcefully, that is, without stopping jobs first. From Oracle Database 11g Release 2.

UNIX and Linux only

-status

Returns this information about the Scheduler Agent running locally: version, uptime, total number of jobs run since the agent started, number of jobs currently running, and their descriptions.

-registerdatabase

Register the Scheduler agent with the base database or additional databases that are to run remote jobs on the agent's host computer.

-unregisterdatabase

Unregister an agent from a database.


Using the Scheduler Agent on Windows

The Windows Scheduler agent service is automatically created and started during installation. The name of the service ends with OracleSchedulerExecutionAgent.

Note:

Do not confuse this service with the OracleJobScheduler service, which runs on a Windows computer on which an Oracle database is installed, and manages the running of local external jobs without credentials.
Starting the Scheduler Agent

Start the Scheduler agent with the following command:

To start the Scheduler agent:

  • Do one of the following:

    • On UNIX and Linux, run the following command:

      AGENT_HOME/bin/schagent -start
      
    • On Windows, start the service whose name ends with OracleSchedulerExecutionAgent.

Stopping the Scheduler Agent

Stopping the Scheduler agent prevents the host on which it resides from running remote jobs.

To stop the Scheduler agent:

  • Do one of the following:

    • On UNIX and Linux, run the schagent utility with either the -stop or -abort option as described in Table 30-1:

      AGENT_HOME/bin/schagent -stop
      
    • On Windows, stop the service whose name ends with OracleSchedulerExecutionAgent. This is equivalent to the -abort option.

Registering Scheduler Agents with Databases

As soon as you have finished configuring the Scheduler Agent, you can register the Agent on one or more databases that are to run remote jobs. You can also log in later on and register the agent with additional databases.

  1. If you have already logged out, then log in to the host that is running the Scheduler agent, as follows:

    • For Windows, log in as an administrator.

    • For UNIX and Linux, log in as the user with which you installed the Scheduler agent.

  2. Use the following command for each database that you want to register the Scheduler agent on:

    • On UNIX and Linux, run this command:

      AGENT_HOME/bin/schagent -registerdatabase db_host db_http_port
      
    • On Windows, run this command:

      AGENT_HOME/bin/schagent.exe -registerdatabase db_host db_http_port
      

    where:

    • db_host is the host name or IP address of the host on which the database resides. In an Oracle Real Application Clusters environment, you can specify any node.

    • db_http_port is the port number that the database listens on for HTTP connections. You set this parameter previously in "Enabling and Disabling Databases for Remote Jobs". You can check the port number by submitting the following SQL statement to the database:

      SELECT DBMS_XDB.GETHTTPPORT() FROM DUAL;
      

      A port number of 0 means that HTTP connections are disabled.

    The agent prompts you to enter the agent registration password that you set in "Enabling and Disabling Databases for Remote Jobs".

  3. Repeat the previous steps for any additional databases to run remote jobs on the agent's host.

Monitoring and Managing the Scheduler

The following sections discuss how to monitor and manage the Scheduler:

Viewing the Currently Active Window and Resource Plan

You can view the currently active window and the plan associated with it by issuing the following statement:

SELECT WINDOW_NAME, RESOURCE_PLAN FROM DBA_SCHEDULER_WINDOWS
WHERE ACTIVE='TRUE';

WINDOW_NAME                    RESOURCE_PLAN
------------------------------ --------------------------
MY_WINDOW10                    MY_RESOURCEPLAN1

If there is no window active, you can view the active resource plan by issuing the following statement:

SELECT * FROM V$RSRC_PLAN;

Finding Information About Currently Running Jobs

You can check a job's state by issuing the following statement:

SELECT JOB_NAME, STATE FROM DBA_SCHEDULER_JOBS
WHERE JOB_NAME = 'MY_EMP_JOB1';

JOB_NAME                       STATE
------------------------------ ---------
MY_EMP_JOB1                    DISABLED

In this case, you could enable the job using the ENABLE procedure. Table 30-2 shows the valid values for job state.

Table 30-2 Job States

Job State Description

disabled

The job is disabled.

scheduled

The job is scheduled to be executed.

running

The job is currently running.

completed

The job has completed, and is not scheduled to run again.

stopped

The job was scheduled to run once and was stopped while it was running.

broken

The job is broken.

failed

The job was scheduled to run once and failed.

retry scheduled

The job has failed at least once and a retry has been scheduled to be executed.

succeeded

The job was scheduled to run once and completed successfully.

chain_stalled

The job is of type chain and has no steps running, no steps scheduled to run, and no event steps waiting on an event, and the chain evaluation_interval is set to NULL. No progress will be made in the chain unless there is manual intervention.


You can check the progress of currently running jobs by issuing the following statement:

SELECT * FROM ALL_SCHEDULER_RUNNING_JOBS;

Note that, for the column CPU_USED to show valid data, the initialization parameter RESOURCE_LIMIT must be set to true.

You can check the status of all jobs at all remote and local destinations by issuing the following statement:

SELECT * FROM DBA_SCHEDULER_JOB_DESTS;

You can find out information about a job that is part of a running chain by issuing the following statement:

SELECT * FROM ALL_SCHEDULER_RUNNING_CHAINS WHERE JOB_NAME='MY_JOB1';

You can check whether the job coordinator is running by searching for a process of the form cjqNNN.

See Also:

Monitoring and Managing Window and Job Logs

The Scheduler supports two kinds of logs: the job log and the window log.

Job Log

You can view information about job runs, job state changes, and job failures in the job log. The job log is implemented as the following two data dictionary views:

  • *_SCHEDULER_JOB_LOG

  • *_SCHEDULER_JOB_RUN_DETAILS

You can control the amount of logging that the Scheduler performs on jobs at both the job class and individual job level. Normally, you control logging at the class level, as this offers you more control over logging for the jobs in the class.

See "Viewing the Job Log" for definitions of the various logging levels and for information about logging level precedence between jobs and their job class. By default, the logging level of job classes is LOGGING_RUNS, which causes all job runs to be logged.

You can set the logging_level attribute when you create the job class, or you can use the SET_ATTRIBUTE procedure to change the logging level at a later time. The following example sets the logging level of jobs in the myclass1 job class to LOGGING_FAILED_RUNS, which means that only failed runs are logged. Note that all job classes are in the SYS schema.

BEGIN
  DBMS_SCHEDULER.SET_ATTRIBUTE (
   'sys.myclass1', 'logging_level', DBMS_SCHEDULER.LOGGING_FAILED_RUNS);
END;
/

You must be granted the MANAGE SCHEDULER privilege to set the logging level of a job class.

See Also:

Window Log

The Scheduler makes an entry in the window log each time that:

  • You create or drop a window

  • A window opens

  • A window closes

  • Windows overlap

  • You enable or disable a window

There are no logging levels for window activity logging.

To see the contents of the window log, query the DBA_SCHEDULER_WINDOW_LOG view. The following statement shows sample output from this view:

SELECT log_id, to_char(log_date, 'DD-MON-YY HH24:MI:SS') timestamp,
   window_name, operation FROM DBA_SCHEDULER_WINDOW_LOG;

    LOG_ID TIMESTAMP            WINDOW_NAME       OPERATION
---------- -------------------- ----------------- --------
         4 10/01/2004 15:29:23  WEEKEND_WINDOW    CREATE
         5 10/01/2004 15:33:01  WEEKEND_WINDOW    UPDATE
        22 10/06/2004 22:02:48  WEEKNIGHT_WINDOW  OPEN
        25 10/07/2004 06:59:37  WEEKNIGHT_WINDOW  CLOSE
        26 10/07/2004 22:01:37  WEEKNIGHT_WINDOW  OPEN
        29 10/08/2004 06:59:51  WEEKNIGHT_WINDOW  CLOSE

The DBA_SCHEDULER_WINDOWS_DETAILS view provides information about every window that was active and is now closed (completed). The following statement shows sample output from that view:

SELECT LOG_ID, WINDOW_NAME, ACTUAL_START_DATE, ACTUAL_DURATION
  FROM DBA_SCHEDULER_WINDOW_DETAILS;

    LOG_ID WINDOW_NAME      ACTUAL_START_DATE                    ACTUAL_DURATION
---------- ---------------- ------------------------------------ ---------------
        25 WEEKNIGHT_WINDOW 06-OCT-04 10:02.48.832438 PM PST8PDT +000 01:02:32
        29 WEEKNIGHT_WINDOW 07-OCT-04 10.01.37.025704 PM PST8PDT +000 03:02:00

Notice that log IDs correspond in both of these views, and that in this case the rows in the DBA_SCHEDULER_WINDOWS_DETAILS view correspond to the CLOSE operations in the DBA_SCHEDULER_WINDOW_LOG view.

See Also:

Purging Logs

To prevent job and window logs from growing indiscriminately, use the SET_SCHEDULER_ATTRIBUTE procedure to specify how much history (in days) to keep. Once per day, the Scheduler automatically purges all log entries that are older than the specified history period from both the job log and the window log. The default history period is 30 days. For example, to change the history period to 90 days, issue the following statement:

DBMS_SCHEDULER.SET_SCHEDULER_ATTRIBUTE('log_history','90');

Some job classes are more important than others. Because of this, you can override this global history setting by using a class-specific setting. For example, suppose that there are three job classes (class1, class2, and class3), and that you want to keep 10 days of history for the window log, class1, and class3, but 30 days for class2. To achieve this, issue the following statements:

DBMS_SCHEDULER.SET_SCHEDULER_ATTRIBUTE('log_history','10');
DBMS_SCHEDULER.SET_ATTRIBUTE('class2','log_history','30');

You can also set the class-specific history when creating the job class.

Note that log entries pertaining to steps of a chain run are not purged until the entries for the main chain job are purged.

Purging Logs Manually

The PURGE_LOG procedure enables you to manually purge logs. As an example, the following statement purges all entries from both the job and window logs:

DBMS_SCHEDULER.PURGE_LOG();

Another example is the following, which purges all entries from the jog log that are older than three days. The window log is not affected by this statement.

DBMS_SCHEDULER.PURGE_LOG(log_history => 3, which_log => 'JOB_LOG');

The following statement purges all window log entries older than 10 days and all job log entries older than 10 days that relate to job1 and to the jobs in class2:

DBMS_SCHEDULER.PURGE_LOG(log_history => 10, job_name => 'job1, sys.class2');

Managing Scheduler Security

You should grant the CREATE JOB system privilege to regular users who need to be able to use the Scheduler to schedule and run jobs. You should grant MANAGE SCHEDULER to any database administrator who must be able to manage system resources. Granting any other Scheduler system privilege or role should not be done without great caution. In particular, the CREATE ANY JOB system privilege and the SCHEDULER_ADMIN role, which includes it, are very powerful because they allow execution of code as any user. They should only be granted to very powerful roles or users.

A particularly important issue from a security point of view is handling external jobs. Only users that need to run jobs outside of the database should be allowed to do so. You must grant the CREATE EXTERNAL JOB system privilege to those users. Security for the Scheduler has no other special requirements. See Oracle Database Security Guide for details regarding security.

Note:

When upgrading from Oracle Database 10g Release 1 to Oracle Database 10g Release 2 or later, CREATE EXTERNAL JOB is automatically granted to all users and roles that have the CREATE JOB privilege. Oracle recommends that you revoke this privilege from users that do not need it.

Import/Export and the Scheduler

You must use the Data Pump utilities (impdp and expdp) to export Scheduler objects. You cannot use the earlier import/export utilities (IMP and EXP) with the Scheduler. Also, Scheduler objects cannot be exported while the database is in read-only mode.

An export generates the DDL that was used to create the Scheduler objects. All attributes are exported. When an import is done, all the database objects are re-created in the new database. All schedules are stored with their time zones, which are maintained in the new database. For example, schedule "Monday at 1 PM PST in a database in San Francisco" would be the same if it was exported and imported to a database in Germany.

Although Scheduler credentials are exported, for security reasons, the passwords in these credentials are not exported. After you import Scheduler credentials, you must reset the passwords using the SET_ATTRIBUTE procedure of the DBMS_SCHEDULER package.

See Also:

Oracle Database Utilities for details on Data Pump

Troubleshooting the Scheduler

This section contains the following troubleshooting topics:

A Job Does Not Run

A job may fail to run for several reasons. To begin troubleshooting a job that you suspect did not run, check the job state by issuing the following statement:

SELECT JOB_NAME, STATE FROM DBA_SCHEDULER_JOBS;

Typical output will resemble the following:

JOB_NAME                       STATE
------------------------------ ---------
MY_EMP_JOB                     DISABLED
MY_EMP_JOB1                    FAILED
MY_NEW_JOB1                    DISABLED
MY_NEW_JOB2                    BROKEN
MY_NEW_JOB3                    COMPLETED

About Job States

There a four states that a job could be in if it does not run:

Failed Jobs

If a job has the status of FAILED in the job table, it was scheduled to run once but the execution has failed. If the job was specified as restartable, all retries have failed.

If a job fails in the middle of execution, only the last transaction of that job is rolled back. If your job executes multiple transactions, then you must be careful about setting restartable to TRUE. You can query failed jobs by querying the *_SCHEDULER_JOB_RUN_DETAILS views.

Broken Jobs

A broken job is one that has exceeded a certain number of failures. This number is set in max_failures, and can be altered. In the case of a broken job, the entire job is broken, and it will not be run until it has been fixed. For debugging and testing, you can use the RUN_JOB procedure.

You can query broken jobs by querying the *_SCHEDULER_JOBS and *_SCHEDULER_JOB_LOG views.

Disabled Jobs

A job can become disabled for the following reasons:

  • The job was manually disabled

  • The job class it belongs to was dropped

  • The program, chain, or schedule that it points to was dropped

  • A window or window group is its schedule and the window or window group is dropped

Completed Jobs

A job will be completed if end_date or max_runs is reached. (If a job recently completed successfully but is scheduled to run again, the job state is SCHEDULED.)

Viewing the Job Log

An important troubleshooting tool is the job log. For details and instructions, see "Viewing the Job Log".

Troubleshooting Remote Jobs

Remote jobs must successfully communicate with a Scheduler agent on the remote host. If a remote job does not run, check the DBA_SCHEDULER_JOBS view and the job log first. Then perform the following tasks:

  1. Check that the remote system is reachable over the network with tools such as nslookup and ping.

  2. Check the status of the Scheduler agent on the remote host by calling the GET_AGENT_VERSION package procedure.

    DECLARE 
      versionnum VARCHAR2(30);
    BEGIN
      versionnum := DBMS_SCHEDULER.GET_AGENT_VERSION('remote_host.example.com');
      DBMS_OUTPUT.PUT_LINE(versionnum);
    END;
    /
    

    If an error is generated, the agent may not be installed or may not be registered with your local database. See "Enabling and Disabling Databases for Remote Jobs" for instructions for installing, registering, and starting the Scheduler agent.

About Job Recovery After a Failure

The Scheduler attempts to recover jobs that are interrupted when:

  • The database abnormally shuts down

  • A job slave process is killed or otherwise fails

  • For an external job, the external job process that starts the executable or script is killed or otherwise fails. (The external job process is extjob on UNIX. On Windows, it is the external job service.)

  • For an external job, the process that runs the end-user executable or script is killed or otherwise fails.

Job recovery proceeds as follows:

  • The Scheduler adds an entry to the job log for the instance of the job that was running when the failure occurred. In the log entry, the OPERATION is 'RUN', the STATUS is 'STOPPED', and ADDITIONAL_INFO contains one of the following:

    • REASON="Job slave process was terminated"

    • REASON="ORA-01014: ORACLE shutdown in progress"

  • If restartable is set to TRUE for the job, the job is restarted.

  • If restartable is set to FALSE for the job:

    • If the job is a run-once job and auto_drop is set to TRUE, the job run is done and the job is dropped.

    • If the job is a run-once job and auto_drop is set to FALSE, the job is disabled and the job state is set to 'STOPPED'.

    • If the job is a repeating job, the Scheduler schedules the next job run and the job state is set to 'SCHEDULED'.

When a job is restarted as a result of this recovery process, the new run is entered into the job log with the operation 'RECOVERY_RUN'.

A Program Becomes Disabled

A program can become disabled if a program argument is dropped or number_of_arguments is changed so that all arguments are no longer defined.

See "Creating and Managing Programs to Define Jobs" for more information regarding programs.

A Window Fails to Take Effect

A window can fail to take effect for the following reasons:

  • A window becomes disabled when it is at the end of its schedule

  • A window that points to a schedule that no longer exists is disabled

See "Managing Job Scheduling and Job Priorities with Windows" for more information regarding windows.

Examples of Using the Scheduler

This section discusses the following topics:

Examples of Creating Job Classes

This section contains several examples of creating job classes. To create a job class, you use the CREATE_JOB_CLASS procedure.

Example 30-1 Creating a Job Class

The following statement creates a job class:

BEGIN
  DBMS_SCHEDULER.CREATE_JOB_CLASS (
   job_class_name              =>  'my_class1',
   service                     =>  'my_service1', 
   comments                    =>  'This is my first job class');
END;
/

This creates my_class1 in SYS. It uses a service called my_service1. To verify that the job class was created, issue the following statement:

SELECT JOB_CLASS_NAME FROM DBA_SCHEDULER_JOB_CLASSES
WHERE JOB_CLASS_NAME = 'MY_CLASS1';

JOB_CLASS_NAME
------------------------------
MY_CLASS1

Example 30-2 Creating a Job Class

The following statement creates a job class:

BEGIN
  DBMS_SCHEDULER.CREATE_JOB_CLASS (
   job_class_name             =>  'finance_jobs', 
   resource_consumer_group    =>  'finance_group',
   service                    =>  'accounting',
   comments                   =>  'All finance jobs');
END;
/

This creates finance_jobs in SYS. It assigns a resource consumer group called finance_group, and designates service affinity for the accounting service. Note that if the accounting service is mapped to a resource consumer group other than finance_group, jobs in this class run under the finance_group consumer group, because the resource_consumer_group attribute takes precedence.

See Also:

Oracle Database PL/SQL Packages and Types Reference for detailed information about the CREATE_JOB_CLASS procedure and "Creating Job Classes" for further information

Examples of Setting Attributes

This section contains several examples of setting attributes. To set attributes, you use SET_ATTRIBUTE and SET_SCHEDULER_ATTRIBUTE procedures.

Example 30-3 Setting the Repeat Interval Attribute

The following example resets the frequency my_emp_job1 will run to daily:

BEGIN
  DBMS_SCHEDULER.SET_ATTRIBUTE (
   name           =>   'my_emp_job1',
   attribute      =>   'repeat_interval',
   value          =>   'FREQ=DAILY');
END;
/

To verify the change, issue the following statement:

SELECT JOB_NAME, REPEAT_INTERVAL FROM DBA_SCHEDULER_JOBS
WHERE JOB_NAME =  'MY_EMP_JOB1';

JOB_NAME             REPEAT_INTERVAL
----------------     ---------------
MY_EMP_JOB1          FREQ=DAILY

Example 30-4 Setting Multiple Job Attributes for a Set of Jobs

The following example sets four different attributes for each of five jobs:

DECLARE
 newattr sys.jobattr;
 newattrarr sys.jobattr_array;
 j number;
BEGIN
 -- Create new JOBATTR array
 newattrarr := sys.jobattr_array();

 -- Allocate enough space in the array
 newattrarr.extend(20);
 j := 1;
 FOR i IN 1..5 LOOP
   -- Create and initialize a JOBATTR object type
   newattr := sys.jobattr(job_name => 'TESTJOB' || to_char(i),
                          attr_name => 'MAX_FAILURES',
                          attr_value => 5);
   -- Add it to the array.
   newattrarr(j) := newattr;
   j := j + 1;
   newattr := sys.jobattr(job_name => 'TESTJOB' || to_char(i),
                          attr_name => 'COMMENTS',
                          attr_value => 'Test job');
   newattrarr(j) := newattr;
   j := j + 1;
   newattr := sys.jobattr(job_name => 'TESTJOB' || to_char(i),
                          attr_name => 'END_DATE',
                          attr_value => systimestamp + interval '24' hour);
   newattrarr(j) := newattr;
   j := j + 1;
   newattr := sys.jobattr(job_name => 'TESTJOB' || to_char(i),
                          attr_name => 'SCHEDULE_LIMIT',
                          attr_value => interval '1' hour);
   newattrarr(j) := newattr;
   j := j + 1;
 END LOOP;

 -- Call SET_JOB_ATTRIBUTES to set all 20 set attributes in one transaction
 DBMS_SCHEDULER.SET_JOB_ATTRIBUTES(newattrarr, 'TRANSACTIONAL');
END;
/

See Also:

Oracle Database PL/SQL Packages and Types Reference for detailed information about the SET_SCHEDULER_ATTRIBUTE procedure and "Setting Scheduler Preferences"

Examples of Creating Chains

This section contains examples of creating chains. To create chains, you use the CREATE_CHAIN procedure. After creating a chain, you add steps to the chain with the DEFINE_CHAIN_STEP or DEFINE_CHAIN_EVENT_STEP procedures and define the rules with the DEFINE_CHAIN_RULE procedure.

Example 30-5 Creating a Chain

The following example creates a chain where my_program1 runs before my_program2 and my_program3. my_program2 and my_program3 run in parallel after my_program1 has completed.

The user for this example must have the CREATE EVALUATION CONTEXT, CREATE RULE, and CREATE RULE SET privileges. See "Setting Chain Privileges" for more information.

BEGIN
  DBMS_SCHEDULER.CREATE_CHAIN (
   chain_name            =>  'my_chain1',
   rule_set_name         =>  NULL,
   evaluation_interval   =>  NULL,
   comments              =>  NULL);
END;
/
 
--- define three steps for this chain. Referenced programs must be enabled.
BEGIN
 DBMS_SCHEDULER.DEFINE_CHAIN_STEP('my_chain1', 'stepA', 'my_program1');
 DBMS_SCHEDULER.DEFINE_CHAIN_STEP('my_chain1', 'stepB', 'my_program2');
 DBMS_SCHEDULER.DEFINE_CHAIN_STEP('my_chain1', 'stepC', 'my_program3');
END;
/

--- define corresponding rules for the chain.
BEGIN
 DBMS_SCHEDULER.DEFINE_CHAIN_RULE('my_chain1', 'TRUE', 'START stepA');
 DBMS_SCHEDULER.DEFINE_CHAIN_RULE (
   'my_chain1', 'stepA COMPLETED', 'Start stepB, stepC');
 DBMS_SCHEDULER.DEFINE_CHAIN_RULE (
   'my_chain1', 'stepB COMPLETED AND stepC COMPLETED', 'END');
END;
/

--- enable the chain
BEGIN
 DBMS_SCHEDULER.ENABLE('my_chain1');
END;
/

--- create a chain job to start the chain daily at 1:00 p.m.
BEGIN
 DBMS_SCHEDULER.CREATE_JOB (
   job_name        => 'chain_job_1',
   job_type        => 'CHAIN',
   job_action      => 'my_chain1',
   repeat_interval => 'freq=daily;byhour=13;byminute=0;bysecond=0',
   enabled         => TRUE);
END;
/

Example 30-6 Creating a Chain

The following example creates a chain where first my_program1 runs. If it succeeds, my_program2 runs; otherwise, my_program3 runs.

BEGIN
 DBMS_SCHEDULER.CREATE_CHAIN (
   chain_name            => 'my_chain2',
   rule_set_name         => NULL,
   evaluation_interval   => NULL,
   comments              => NULL);
END;
/
 
--- define three steps for this chain.
BEGIN
 DBMS_SCHEDULER.DEFINE_CHAIN_STEP('my_chain2', 'step1', 'my_program1');
 DBMS_SCHEDULER.DEFINE_CHAIN_STEP('my_chain2', 'step2', 'my_program2');
 DBMS_SCHEDULER.DEFINE_CHAIN_STEP('my_chain2', 'step3', 'my_program3');
END;
/
 
--- define corresponding rules for the chain.
BEGIN
 DBMS_SCHEDULER.DEFINE_CHAIN_RULE ('my_chain2', 'TRUE', 'START step1');
 DBMS_SCHEDULER.DEFINE_CHAIN_RULE (
   'my_chain2', 'step1 SUCCEEDED', 'Start step2');
 DBMS_SCHEDULER.DEFINE_CHAIN_RULE (
   'my_chain2', 'step1 COMPLETED AND step1 NOT SUCCEEDED', 'Start step3');
 DBMS_SCHEDULER.DEFINE_CHAIN_RULE (
   'my_chain2', 'step2 COMPLETED OR step3 COMPLETED', 'END');
END;
/

See Also:

Oracle Database PL/SQL Packages and Types Reference for detailed information about the CREATE_CHAIN, DEFINE_CHAIN_STEP, and DEFINE_CHAIN_RULE procedures and "Setting Scheduler Preferences"

Examples of Creating Jobs and Schedules Based on Events

This section contains examples of creating event-based jobs and event schedules. To create event-based jobs, you use the CREATE_JOB procedure. To create event-based schedules, you use the CREATE_EVENT_SCHEDULE procedure.

These examples assume the existence of an application that, when it detects the arrival of a file on a system, enqueues an event onto the queue my_events_q.

Example 30-7 Creating an Event-Based Schedule

The following example illustrates creating a schedule that can be used to start a job whenever the Scheduler receives an event indicating that a file arrived on the system before 9AM:

BEGIN
  DBMS_SCHEDULER.CREATE_EVENT_SCHEDULE (
   schedule_name     =>  'scott.file_arrival',
   start_date        =>  systimestamp,
   event_condition   =>  'tab.user_data.object_owner = ''SCOTT'' 
      and tab.user_data.event_name = ''FILE_ARRIVAL'' 
      and extract hour from tab.user_data.event_timestamp < 9',
   queue_spec        =>  'my_events_q');
END;
/

Example 30-8 Creating an Event-Based Job

The following example creates a job that starts when the Scheduler receives an event indicating that a file arrived on the system:

BEGIN
  DBMS_SCHEDULER.CREATE_JOB (
   job_name            =>  my_job,
   program_name        =>  my_program,
   start_date          =>  '15-JUL-04 1.00.00AM US/Pacific',
   event_condition     =>  'tab.user_data.event_name = ''LOW_INVENTORY''',
   queue_spec          =>  'my_events_q'
   enabled             =>  TRUE,
   comments            =>  'my event-based job');
END;
/

See Also:

Oracle Database PL/SQL Packages and Types Reference for detailed information about the CREATE_JOB and CREATE_EVENT_SCHEDULE procedures

Example of Creating a Job In an Oracle Data Guard Environment

In an Oracle Data Guard environment, the Scheduler includes additional support for two database roles: primary and logical standby. You can configure a job to run only when the database is in the primary role or only when the database is in the logical standby role. To do so, you set the database_role attribute. This example explains how to enable a job to run in both database roles. The method used is to create two copies of the job and assign a different database_role attribute to each.

By default, a job runs when the database is in the role that it was in when the job was created. You can run the same job in both roles using the following steps:

  1. Copy the job

  2. Enable the new job

  3. Change the database_role attribute of the new job to the required role

The example starts by creating a job called primary_job on the primary database. It then makes a copy of this job and sets its database_role attribute to 'LOGICAL STANDBY'. If the primary database then becomes a logical standby, the job continues to run according to its schedule.

When you copy a job, the new job is disabled, so you must enable the new job.

BEGIN DBMS_SCHEDULER.CREATE_JOB (
     job_name       => 'primary_job',
     program_name   => 'my_prog',
     schedule_name  => 'my_sched');

 DBMS_SCHEDULER.COPY_JOB('primary_job','standby_job');
 DBMS_SCHEDULER.ENABLE(name=>'standby_job', commit_semantics=>'ABSORB_ERRORS');
 DBMS_SCHEDULER.SET_ATTRIBUTE('standby_job','database_role','LOGICAL STANDBY');
END;
/

After you execute this example, the data in the DBA_SCHEDULER_JOB_ROLES view is as follows:

SELECT JOB_NAME, DATABASE_ROLE FROM DBA_SCHEDULER_JOB_ROLES
   WHERE JOB_NAME IN ('PRIMARY_JOB','STANDBY_JOB');

JOB_NAME               DATABASE_ROLE
--------               ----------------
PRIMARY_JOB            PRIMARY
STABDBY_JOB            LOGICAL STANDBY

Note:

For a physical standby database, any changes made to Scheduler objects or any database changes made by Scheduler jobs on the primary database are applied to the physical standby like any other database changes.

Scheduler Reference

This section contains reference information for Oracle Scheduler. It contains the following topics:

Scheduler Privileges

Table 30-3, "Scheduler System Privileges" and Table 30-4, "Scheduler Object Privileges" describe the various Scheduler privileges.

Table 30-3 Scheduler System Privileges

Privilege Name Operations Authorized

CREATE JOB

This privilege enables you to create jobs, chains, schedules, programs, file watchers, credentials, destinations, and groups in your own schema. You can always alter and drop these objects in your own schema, even if you do not have the CREATE JOB privilege. In this case, the object would have been created in your schema by another user with the CREATE ANY JOB privilege.

CREATE ANY JOB

This privilege enables you to create, alter, and drop jobs, chains, schedules, programs, file watchers, credentials, destinations, and groups in any schema except SYS. This privilege is extremely powerful and should be used with care because it allows the grantee to execute any PL/SQL code as any other database user.

CREATE EXTERNAL JOB

This privilege is required to create jobs that run outside of the database. Owners of jobs of type 'EXECUTABLE' or jobs that point to programs of type 'EXECUTABLE' require this privilege. To run a job of type 'EXECUTABLE', you must have this privilege and the CREATE JOB privilege. This privilege is also required to retrieve files from a remote host and to save files to one or more remote hosts.

EXECUTE ANY PROGRAM

This privilege enables your jobs to use programs or chains from any schema.

EXECUTE ANY CLASS

This privilege enables your jobs to run under any job class.

MANAGE SCHEDULER

This is the most important privilege for administering the Scheduler. It enables you to create, alter, and drop job classes, windows, and window groups, and to stop jobs with the force option. It also enables you to set and retrieve Scheduler attributes, purge Scheduler logs, and set the agent password for a database.


Table 30-4 Scheduler Object Privileges

Privilege Name Operations Authorized

SELECT

You can grant object privileges on a group to other users by granting SELECT on the group.

EXECUTE

You can grant this privilege only on programs, chains, file watchers, credentials, and job classes. The EXECUTE privilege enables you to reference the object in a job. It also enables you to view the object if the object is was not created in your schema.

ALTER

This privilege enables you to alter or drop the object it is granted on. Altering includes such operations as enabling, disabling, defining or dropping program arguments, setting or resetting job argument values and running a job. Certain restricted attributes of jobs of job type EXECUTABLE cannot be altered using the ALTER object privilege. These include job_type, job_action, number_of_arguments, event_spec, and setting PL/SQL date functions as schedules.

For programs, jobs, chains, file watchers, and credentials, this privilege also enables schemas that do not own these objects to view them. This privilege can be granted on jobs, chains, programs, schedules, file watchers, and credentials. For other types of Scheduler objects, you must grant the MANAGE SCHEDULER system privilege.

ALL

This privilege authorizes operations allowed by all other object privileges possible for a given object. It can be granted on jobs, programs, chains, schedules, file watchers, credentials, and job classes.


Note:

No object privileges are required to use a destination object created by another user.

The SCHEDULER_ADMIN role is created with all of the system privileges shown in Table 30-3 (with the ADMIN option). The SCHEDULER_ADMIN role is granted to DBA (with the ADMIN option).

The DBMS_SCHEDULER package ignores privileges granted on scheduler objects, such as jobs or chains, through roles. Object privileges must be granted directly to the user.

The following object privileges are granted to PUBLIC: SELECT ALL_SCHEDULER_* views, SELECT USER_SCHEDULER_* views, SELECT SYS.SCHEDULER$_JOBSUFFIX_S (for generating a job name), and EXECUTE SYS.DEFAULT_JOB_CLASS.

Scheduler Data Dictionary Views

You can check Scheduler information by using many views. An example is the following, which shows information for completed instances of my_job1:

SELECT JOB_NAME, STATUS, ERROR#
FROM DBA_SCHEDULER_JOB_RUN_DETAILS WHERE JOB_NAME = 'MY_JOB1';

JOB_NAME     STATUS           ERROR#
--------     --------------   ------
MY_JOB1      FAILURE           20000

Table 30-5 contains views associated with the Scheduler. The *_SCHEDULER_JOBS, *_SCHEDULER_SCHEDULES, *_SCHEDULER_PROGRAMS, *_SCHEDULER_RUNNING_JOBS, *_SCHEDULER_JOB_LOG, *_SCHEDULER_JOB_RUN_DETAILS views are particularly useful for managing jobs. See Oracle Database Reference for details regarding Scheduler views.

Note:

In the following table, the asterisk at the beginning of a view name can be replaced with DBA, ALL, or USER.

Table 30-5 Scheduler Views

View Description
*_SCHEDULER_CHAIN_RULES

These views show all rules for all chains.

*_SCHEDULER_CHAIN_STEPS

These views show all steps for all chains.

*_SCHEDULER_CHAINS

These views show all chains.

*_SCHEDULER_CREDENTIALS

These views show all credentials.

*_SCHEDULER_DB_DESTS

These views show all database destinations.

*_SCHEDULER_DESTS

These views show all destinations, both database and external.

*_SCHEDULER_EXTERNAL_DESTS

These views show all external destinations.

*_SCHEDULER_FILE_WATCHERS

These views show all file watchers.

*_SCHEDULER_GLOBAL_ATTRIBUTE

These views show the current values of Scheduler attributes.

*_SCHEDULER_GROUP_MEMBERS

These views show all group members in all groups.

*_SCHEDULER_GROUPS

These views show all groups.

*_SCHEDULER_JOB_ARGS

These views show all set argument values for all jobs.

*_SCHEDULER_JOB_CLASSES

These views show all job classes.

*_SCHEDULER_JOB_DESTS

These views show the state of both local jobs and jobs at remote destinations, including child jobs of multiple-destination jobs. You obtain job destination IDs (job_dest_id) from these views.

*_SCHEDULER_JOB_LOG

These views show job runs and state changes, depending on the logging level set.

*_SCHEDULER_JOB_ROLES

These views show all jobs by Oracle Data Guard database role.

*_SCHEDULER_JOB_RUN_DETAILS

These views show all completed (failed or successful) job runs.

*_SCHEDULER_JOBS

These views show all jobs, enabled as well as disabled.

*_SCHEDULER_NOTIFICATIONS

These views show all job state e-mail notifications.

*_SCHEDULER_PROGRAM_ARGS

These views show all arguments defined for all programs as well as the default values if they exist.

*_SCHEDULER_PROGRAMS

These views show all programs.

*_SCHEDULER_RUNNING_CHAINS

These views show all chains that are running.

*_SCHEDULER_RUNNING_JOBS

These views show state information on all jobs that are currently being run.

*_SCHEDULER_SCHEDULES

These views show all schedules.

*_SCHEDULER_WINDOW_DETAILS

These views show all completed window runs.

*_SCHEDULER_WINDOW_GROUPS

These views show all window groups.

*_SCHEDULER_WINDOW_LOG

These views show all state changes made to windows.

*_SCHEDULER_WINDOWS

These views show all windows.

*_SCHEDULER_WINGROUP_MEMBERS

These views show the members of all window groups, one row for each group member.