17 Oracle Business Activity Monitoring

This chapter describes issues associated with Oracle Business Activity Monitoring. It includes the following topics:

17.1 General Issues and Workarounds

This section describes general issue and workarounds. It includes the following topics:

17.1.1 Oracle BAM Client System Requirements

Platforms:

Microsoft Windows Intel x86-32:

  • Microsoft Windows XP Professional, Service Pack 2 or higher

  • Microsoft Windows Vista

Web Browsers: 

  • Microsoft Internet Explorer 7.x

  • Microsoft Internet Explorer 8.x

Hardware: 

  • 1 CPU at 1.2 GHz or faster minimum (a faster processor may be necessary to view complex dashboards)

  • 512 MB RAM minimum

  • 5 MB of free disk space

Display: 

  • Oracle BAM Active Studio requires 1024 x 768 minimum resolution

  • Oracle BAM Active Viewer requires 800 x 600 or higher resolution

Additional Requirements for Optional Excel View in Oracle BAM Active Viewer or Oracle BAM Active Studio:

The Oracle BAM Excel view type requires that Microsoft Excel version XP, 2003, or 2007 is installed on the client computer.

Notes:

If you are using the Microsoft Windows pop-up blocker, or any other tool that blocks pop-up browser windows, you must configure it to allow pop-up windows while using the Oracle BAM Web applications. Turn off pop-up blockers in Microsoft Internet Explorer for the URL on which the Oracle BAM Web applications are hosted.

The Microsoft Internet Explorer installation on client systems must be a standard version, and it must not include customizations such as add-in tool bars or hot bars for other Web sites.

17.1.2 New Product Features in This Release

The following are new Oracle BAM features in this release:

  • Oracle BAM data control for ADF development in Oracle JDeveloper

  • Monitor Express dashboard for displaying BPEL monitoring object data

  • Microsoft Internet Explorer 8 certification

  • Enable and disable BPEL sensors (including Oracle BAM sensors) in BPEL processes at the global level in Oracle Enterprise Manager Fusion Middleware Control and at the project-level in Oracle JDeveloper.

  • Oracle BAM Architect user interface enhancements for Enterprise Message Sources

  • Improved Alert diagnostics in Oracle BAM Active Studio

  • Improved purge (delete rows from a data object) Alert performance

  • Configure Oracle BAM Adapter properties using Oracle WebLogic Server Administrative Console

  • Support for datetime and timestamp filters to work in user preferred time zone

See the Oracle BAM page on the Oracle Technology Network Web site for additional information about this release:

http://www.oracle.com/technology/products/integration/bam

17.1.3 Some Product Features Previews Only

Preview features are for evaluation only.

ICommand Web Service is a preview feature.

Saving reports in MHT format is a preview feature. Save Offline, e-mailing rendered reports, and e-mailing a report in Alerts save the report in the MHT format.

The following report views are preview versions: P-Chart, R-Chart, S-Chart, Columnar, Crosstab, Summary Crosstab, Matrix, Excel, Column Group, and Row Group.

17.1.4 Accessibility Compliance Limitation

This version of Oracle BAM does not comply with accessibility standards provided in other Oracle products. Future versions plan to comply with these standards.

17.1.5 Oracle BAM Upgrade-Related Issues

For a complete list of Oracle BAM upgrade issues, see the following sections:

17.1.6 JDBC Data Source Statement-Cache-Size Must Be Set to Zero For Oracle BAM

For single instance database installs, the statement cache size will already be set to 0 (zero) by default. Do not change this to a non-zero value.

For installs against a RAC database, the statement cache size must manually be set to 0 for each RAC data source; otherwise, data corruption may occur and the Oracle BAM Active Data Cache may need to be restored from a backup (or reinitialized if no backups are available).

17.1.7 Database Must Be Started Before Oracle BAM

Oracle BAM applications are not functional if the database on which Oracle BAM depends is started few minutes later than Oracle BAM Server.

17.1.8 Batched Messages Lost on BPEL Server Restart

An Oracle BAM sensor action cannot be notified of BPEL events, and the messages sent to Oracle BAM from the BPEL server are only stored in memory; therefore, when the BPEL server restarts, all the messages still on the BPEL side are lost.

This behavior is by design, and there is no workaround.

17.1.9 Oracle Data Integrator IKM and LKM Operations For Oracle BAM Fail During RAC or Whole Server Migration Failover

When an interface involving Oracle BAM IKM and LKM modules is in execution when either the RAC database fails over or Oracle BAM Server undergoes whole server migration, then, at the instant that the failover starts, the Oracle Data Integrator session reports an exception for that particular step, and the execution for the entire interface is halted.

The user will have to re-execute that interface. If commit size was set to zero (for any of the IKM SQL to Oracle BAM-based interfaces), the entire transaction is rolled back. In those cases where a different commit size was used, the user will have to take adequate steps to avoid data duplication in the target data store upon re-execution.

17.1.10 Limitations With Single EAR and Two Oracle BAM Targets in Oracle Enterprise Manager Fusion Middleware Control

Oracle BAM presents the following limitations because in this release Oracle BAM Web applications and Oracle BAM Server are only deployed in a single EAR, but are represented in Oracle Enterprise Manager Fusion Middleware Control using two separate targets:

  • Along with two custom targets, Oracle BAM Server and Oracle BAM Web applications, The Oracle BAM application also appears as a generic J2EE application in the Application Deployments list in Oracle Enterprise Manager Fusion Middleware Control navigation tree, and in the Farm home page. It is recommended that the user only use custom Oracle BAM targets (OracleBAMServer and OracleBAMWeb), the internal application target (oracle-bam) should not be used.

    Additional information about the generic oracle-bam J2EE application target: The generic J2EE application target (oracle-bam) despite being an internal application, still appears under parent Application Deployments and not in the sub-folder Internal Applications of Application Deployments. Moving oracle-bam generic J2EE application target to Internal Applications folder has been deferred.

  • The Stop and Start commands in the Oracle BAM Server and Oracle BAM Web applications menus in Oracle Enterprise Manager Fusion Middleware Control pages does not stop or start the corresponding target only, it stops the entire Oracle BAM application (Oracle BAM Server and Oracle BAM Web applications).

  • Viewing any J2EE metrics in the context of Oracle BAM Server or Oracle BAM Web applications actually presents the view for entire J2EE application. (From performance page and Oracle WebLogic Server page the user gets access to the J2EE application metric).

  • Oracle WebLogic Server (Managed Server) home page shows three deployed applications for each Oracle BAM install (two custom targets and one generic J2EE application target). Corresponding to each target there are few J2EE application metrics shown. Because J2EE metrics correspond to each deployment, the metrics values get repeated for all of the Oracle BAM targets. The workaround is displaying metric values only against one target and the other two showing n/a.

17.1.11 Oracle Enterprise Manager Fusion Middleware Control MBean Browser Does Not Validate Values

The MBean browser in Oracle Enterprise Manager Fusion Middleware Control does not have any validation in place to check whether the entered value is correct or not.

17.1.12 Unable To Extend Tablespace

When you see the Unable to extend tablespace error message, you can do the following:

  • Increase the tablespace size.

  • If you cleared a large amount of data from a data object, and expect the tablespace to have more data, you might still see this error. The table space release is not synchronous, and you must run command ALTER TABLE table_name SHRINK SPACE.

17.1.13 Unable to Create or View Report With User With No Permissions on System Folder

A user assigned to a non-Administrator role may be unable to create or view reports, but has the privileges to do so, and gets the following error:

DATAOBJECTPERMISSIONMISSINGEXCEPTION_ACTIVESTUDIO_REPORTEDITOR_EDITREPORT

Exception Message BAM-01257: Insufficient permission to perform the requested action.

This is due to the user not having at least Read permissions on the /System folder in Oracle BAM Architect.

17.1.14 Opening Report on Two Systems Causes Language Mix

The same user opening a report on two different computers with different language settings causes a language mix in the Oracle BAM user interface.

A single user should not log in simultaneously on different computers with two different language settings.

17.1.15 Oracle BAM Event Engine Cannot Call WS-Security-Enabled Web Services

As part of an Oracle BAM alert action, Oracle BAM Event Engine can call external Web services. However, for secure Web services, Oracle BAM Event Engine supports calling only HTTP Basic authentication protected Web services. Configuring an alert action to call WS-Security enabled Web services is not supported.

The Web service alert action now supports a couple of basic OWSM security policies namely oracle/wss_http_token_client_policy and oracle/wss_username_token_client_policy. These policies could be used to invoke Web services which are protected by corresponding server side OWSM policies. By default, all secure Web service invocations (requiring user name and password to be passed) would use oracle/wss_http_token_client_policy which essentially makes client to go through BASIC HTTP authentication.

17.1.16 Use Single Quotation Marks in ICommand Web Service Export Command

Using double quotation marks (") around the file value in ICommand export does not work.

Use single quotation marks (') instead of double quotation marks to specify the file value.

<?xml version="1.0" encoding="utf-8"?><IstanteCommands><export name='/Samples/Film Sales' file='c:\do_with_data.xml' type="dataobject"/></IstanteCommands>

17.1.17 Alert Fires Multiple Times Using COUNTDISTINCT Aggregate

When operation COUNTDISTINCT-based aggregate is chosen in Group filters in data object and report based alerts, the user might see the alert firing multiple times, even if the alert criterion was satisfied only once in the data. This behavior is seen when bulk data object operations are performed. That is, if multiple rows are inserted, deleted, updated, or upserted in the data object at one time.

17.1.18 Select Higher Time Groupings in Crosstab Views

Grouping by Week in a Crosstab or Chart view could cause group values for Day of Month or Day of Week to be calculated incorrectly for weeks that include the end of one month and the beginning of another.

Include Day of Year in the grouping along with Day of Month or Day of Week.

17.1.19 Invoking an Oracle Data Integrator Scenario With Date Input From Oracle BAM Alert Rule

When you must pass a date input through an Oracle BAM alert rule invocation to an Oracle Data Integrator scenario, it is recommended that you set up the Oracle Data Integrator scenario to use an alphanumeric type variable instead of date type. Using a date type variable may lead to a parse exception within the Oracle Data Integrator agent which results in a failure to invoke the scenario successfully.

When this alphanumeric type variable is used within the definition of the Oracle Data Integrator interface, use the TO_DATE function along with the format in which the date is expected. For example, with a project level variable named alphVariableName, the function usage would be:

TO_DATE('#alphVariableName','YYYY-MM-DD')

Within the Oracle BAM alert rule definition (for the Run an ODI scenario action), pass the date to be input in the same format.

17.1.20 Do Not Use Time Dimension For Drilling Down in a Collapsed List

Drilling down on a time or date dimension in a collapsed list view causes an exception. Use chart views only to drill down on time or date dimensions.

17.1.21 Active Now Applied After Initial Prompt Creation Shows Error in View

While creating filter on a datetime field, if you create a prompt with is greater than comparison first without configuring Active Now, then later on if you change the prompt from the Change Report Properties dialog to configure Active Now, an error does not appear in the user interface, but when the report view runs it will display an error, because the prompts are stored independently of the views they are used in.

In short, a prompt cannot detect how it is used in a report, so a change in a prompt may produce unexpected results.

17.1.22 Active Now Fails To Drop Rows When the Time Window Advances

If a user designs a report view with a combination of Continuous Time Series on a datetime or timestamp type column, and configures a filter for that column using is within a time interval and enabling Active Now (this combination is also known as Absolute Active Now), at times, the report might not drop or add the rows as the time window advances. This is due to the time boundary mismatch between Absolute Active Now and Continuous Time Series.

Active Now time is based on seconds, and considers the report opening time as its starting point (for example, the report is opened at 10.30:15 AM), and the end point is relative to the starting point.

However, Continuous Time Series considers the upper boundary at the time unit level chosen by the user (for example, the report is configured to use minutes as the time unit, so the starting time is considered to be 10.30:00 AM).

This mismatch in time units causes the report to not add or drop rows until the row has been dropped or added in terms of seconds according to the Absolute Active Now time period.

17.1.23 Chart View Displays Text Instead of a Chart When the Window is Not Initially Maximized

When report is opened in sub-maximal sized Web browser window, a chart view area may display the message "The view area is too small to represent the current data." When the Web browser window is maximized, the message might not be replaced by the expected chart view.

To work around this issue, always launch Oracle BAM reports in maximized Web browser windows.

17.1.24 BPEL Monitor Metric Names in Non-ASCII Characters Causes Deployment Error, Missing Data Object on Oracle BAM Server

Business Indicator monitoring object metric names cannot contain non-ASCII characters. In Oracle BAM Server, only the Component, Counter, and Business Indicator data objects are created correctly. The process-related data object is not created.

17.1.25 Potential Issues with Oracle BAM Order Booking Sample Application

Design-Time Issues

When the sample application archive (SOA_ORACLE_HOME/bam/samples/bam/order_booking/jdev_project/OrderBookingWithBAMSensors.zip) is opened in Oracle JDeveloper, it is possible that you may observe design-time issues, such as broken partnerlink associations or valid database connections that cannot connect to a target database when editing the database adapter, and so on.

It is also possible, that you may sometimes experience problems attempting to run tests using the Oracle Enterprise Manager test console after modifying and redeploying this application to the SOA server.

To avoid these issues, it is recommended that you download a more recent version of the sample application from the Oracle Technology Network Web site located at

http://www.oracle.com/technology/sample_code/products/bam

Oracle Enterprise Manager Test Console Issue

There is a known issue with Oracle Enterprise Manager test console when submitting a datetime type payload.

If a BPEL process requires a datetime type input argument in its payload, and this process is tested using Oracle Enterprise Manager test console, the console drops the time data provided and adds an offset to the date value provided.

For example, an input of 2001-01-01 08:00:00 AM is modified, and reaches the BPEL process as 2000-12-31-08:00. This modification happens when the input was provided using Tree View.

This issue is likely to impact attempts to test the BPEL and Oracle BAM integration, such as when testing the OrderBookingWithBAMSensors sample shipped with Oracle BAM.

It is recommended that you provide the input using XML View rather than Tree View, or enter the inputs in Tree View, then toggle to XML View, review the data, and then submit the test request from the XML View.

For your convenience, use the payload sample below to test the sample application. Copy this payload into the XML View in Oracle Enterprise Manager test console for the OrderBookingBAM BPEL process.

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
   <soap:Body xmlns:ns1="http://www.globalcompany.com/ns/order">
      <ns1:PurchaseOrder>
         <ns1:CustID>10</ns1:CustID>
         <ns1:ID>1</ns1:ID>
         <ns1:ShipTo><ns1:Name/><ns1:Address/></ns1:ShipTo>
         <ns1:BillTo><ns1:Name/><ns1:Address/></ns1:BillTo>
         <ns1:UserContact><ns1:PhoneNumber/><ns1:EmailAddress/></ns1:UserContact>
         <ns1:OrderItems/>
         <ns1:SupplierInfo>
            <ns1:SupplierPrice>10</ns1:SupplierPrice>
            <ns1:SupplierName>SupplierABC</ns1:SupplierName>
         </ns1:SupplierInfo>
         <ns1:OrderInfo>
            <ns1:OrderDate>2001-01-01T15:10:20.000-07:00</ns1:OrderDate>
            <ns1:OrderPrice>25</ns1:OrderPrice>
            <ns1:OrderStatus>open</ns1:OrderStatus>
            <ns1:OrderComments/>
         </ns1:OrderInfo>
      </ns1:PurchaseOrder>
   </soap:Body>
</soap:Envelope>

17.1.26 SSL Connection to Oracle BAM Is Not Supported for Monitor Express

Deployment to Oracle BAM Monitor Express data objects through an SSL connection is not supported.

17.1.27 Updated Oracle BAM Adapter Connection Pool Throws ClassLoaderException

In a SOA composite application, BPEL monitoring objects and Oracle BAM sensor actions can be configured to use RMI or SOAP connection pools from Oracle BAM Adapter.

The problematic scenario involves a SOA composite application in which an Oracle BAM connection resource is initially configured to use the RMI connection pool and deployed to SOA server.

Later, either

1) the application's Oracle BAM connection is updated to use the SOAP connection pool (with batching enabled), or

2) a new BAM sensor action, using the SOAP connection pool (with batching enabled), is configured in the BPEL process.

After redeploying this updated application to SOA server, and posting new requests to the BPEL process, the ClassLoaderException might occur at run time for the BPEL monitoring objects or BAM sensor actions.

Workaround: restart SOA server and Oracle BAM Server.

17.1.28 Providing Incorrect Credentials to Oracle BAM Web Service Call Can Result in Lockout, Incorrect Exception Shown

If an Oracle BAM Web service is invoked using a wrong/invalid credential, then Oracle WebLogic Server will lock out the user due to unsuccessful attempts, depending upon the number of calls to the Web service (For example an Oracle BAM alert invoking the Oracle BAM ReportMailer Web service). Default Oracle WebLogic Server behavior is to lock out a user if they have 5 unsuccessful attempts. User should fix the credentials and restart Oracle BAM Server or disable the Oracle WebLogic Server lockout feature.

In addition, every other alert error handling scenario fails after this. The exception will read "Authentication failed" in Alert History table in Oracle BAM Active Studio.

To disable Oracle WebLogic Server lockout, login to the Oracle WebLogic Server Administrative Console, in the Domain Structure tree, select Security Realms --> myrealm --> User Lockout tab, uncheck Lockout Enabled, and click Save.

17.1.29 Calculated Fields Cannot Use Datetime Type Field

If a user creates a new calculated field using datetime type fields, the Calculations tab displays this error:

BAM-01610: INVALID FILTER EXPRESSION

More specifically, this error occurs when the calculation is an expression for equality check against a datetime field in String format. For example, for a datetime field such as Last Modified, the following calculation does not work:

If {Last Modified}=="7/18/2002 1:33:10 PM"

Also, an upgrade to Oracle BAM release 11.1.1.0 or 11.1.1.2.0 on a report containing calculated fields with datetime fields results in the same error. The datetime field calculated fields must be removed from the report.

17.1.30 Save in Excel 2007 Format Does Not Work

In Oracle BAM Active Studio, when the user attempts to save an Excel view using Microsoft Excel 97-2003 format, it is possible that a message that reads "Excel 2007 or greater is required to edit this Excel view" will appear. This is a known issue.

17.1.31 Matrix View Can Yield Incorrect Results in Certain Situations

In Oracle BAM Active Studio, there may be data mismatch across various fields in a dataobject chosen for building the Matrix view. One such instance is when the data in the field begins a lowercase alphabetic character (for example, "alpha"). The problem is resolved if the field value begins with uppercase alphabetic character (for example, "Alpha"). The Matrix view is a preview feature and this is a known issue.

17.1.32 Failure to Send Message to Oracle BAM is Not Reported on Oracle Fusion Middleware Control Console

The Oracle BAM-BPEL integration is supported with the use of Oracle BAM Adapter (such as with Oracle BAM sensor actions and BPEL Monitor features). For BPEL processes and other services that attempt to send messages to Oracle BAM, the true status of whether such Oracle BAM invocations succeeded or failed cannot be determined by studying the audit trail for that process instance on the Oracle Enterprise Manager Fusion Middleware Control Console. It is intentionally designed such that a failure to send sensor/monitor data to Oracle BAM should not cause the regular processing of input request (within a BPEL process) to be halted/failed. Accordingly, the console will therefore only report the status for the instance based on the non-Oracle BAM related activities. The Oracle BAM Server invocation failures, if any, will be noticeable in the SOA server diagnostic logs.

17.1.33 Tabs Sometimes Missing in Oracle BAM Active Studio

If you are using Microsoft Internet Explorer 8, and Oracle BAM Active Studio or one of the other Oracle BAM Web Applications does not open properly (for example, some of the main user interface tabs do not appear), try refreshing or reloading Oracle BAM Active Studio.

If that workaround does not resolve the issue, close Oracle BAM Active Studio, clear your Internet Explorer browser cache (via Tools > Internet Options > Delete), then reopen Oracle BAM Active Studio.

Alternatively, if the above workarounds do not resolve the issue, add the Oracle BAM Web server to Microsoft Internet Explorer's Trusted sites:

  1. Go to Tools > Internet Options > Security > Trusted sites and click Sites.

  2. Uncheck Require server verification (https:) for all sites in this zone if necessary (it is necessary unless you have Oracle BAM set up for SSL).

  3. Add the Oracle BAM URL to the list:

    http://<bam_servername>

17.1.34 SPC S-Chart Displays Incorrect Limits

The SPC S-Chart view displays incorrect upper control limit (UCL) and lower control limit (LCL) series in the chart.

Although the S-Chart was corrected to display the Standard Deviation, rather than the average, the UCL and LCL value were not corrected. The limits do not correspond to the S-Chart, but they do correspond to the X-bar chart. This is a known issue.

17.1.35 SPC R-Chart Displays Incorrect Chart

The R-Chart view displays an incorrect chart. The R-Chart should plot a Range for the data set, rather than an Average as it currently displays. Also, the upper control limit (UCL) and lower control limit (LCL) values will require correction when moving from Average to Range.

17.2 Documentation Errata

This section describes documentation errata. It includes the following topics:

17.2.1 Updates to Oracle BAM Property Documentation

References to properties in the Oracle Fusion Middleware Administrator's Guide for Oracle SOA Suite are corrected as follows:

Additional Configuration Properties

ActiveDataCache_Datasets_Batching_BlockOnBatchFull and Adapter_SOAP_Batching_BlockOnBatchFull are available for configuration.

The block on batch full properties indicate whether batching operations should block when the batch is full. If set to true, then batching calls block until room is freed up in the batch for the operation. If set to false, a BatchIsFullException exception is thrown.

FlushOnDemand_Limit Property Not Configurable In XML

Because flush-on-demand can only be enabled programmatically, and it is currently not used by Oracle BAM, the FlushOnDemand_Limit properties should not appear in the documentation.

Oracle BAM Adapter Block_On_Batch_Full Default Value

The default values for Block_On_Batch_Full and SOAP_Block_On_Batch_Full are documented incorrectly. The default value for both properties is false.

Oracle BAM ADC API Property Clarification

It is not clearly stated in the documentation that the Oracle BAM ADC API properties are the properties used by all Oracle BAM clients (such as ICommand and Oracle Data Integrator), and the SOAP properties are only used by Oracle BAM Adapter when configured to use SOAP.

17.2.2 SPC S-Chart Behavior Changes

By definition, S charts plot standard deviation values on X-BAR, however, in previous versions of Oracle BAM, S charts plotted average/mean values on X-BAR. In this version of Oracle BAM and going forward, S charts plot standard deviation values on X-BAR.

S chart reports created earlier than this version will continue to show average values instead of standard deviation values. You must recreate the S chart to display standard deviation values on X-bar.

There are still some issues with the S-Chart as noted in Section 17.1.34, "SPC S-Chart Displays Incorrect Limits."

17.2.3 Instructions for Oracle BAM Data Control on SSL-Enabled Oracle BAM Server

To create an Oracle BAM data control against an SSL-enabled Oracle BAM Server Oracle JDeveloper must be started with the -J-Djavax.net.ssl.trustStore option, which should point to the location of the keystore. The connection to Oracle BAM Server cannot be created without this option.

Example:

C:\jdevrc1\jdeveloper\jdev\bin>jdev -J-Djavax.net.ssl.trustStore=C:\jdevrc1\wlserver_10.3\server\lib\DemoTrust.jks

17.2.4 Changes to "Configuring Oracle BAM Adapter Properties" Section

In Oracle Fusion Middleware Administrator's Guide for Oracle SOA Suite, Section 21.7.1 Configuring Oracle BAM Adapter Properties, step 6, the text states "Restart the server."

The server referred to is the SOA domain server. It needs to be restarted because that is where the Oracle BAM Adapter is deployed.

17.2.5 Recommended Memory Settings for Using Oracle Data Integrator with Oracle BAM

The default memory settings for Oracle Data Integrator are included in the odiparams.sh script (or odiparams.bat for windows). The values for the ODI_INIT_HEAP and ODI_MAX_HEAP properties default to 32M and 256M. It is recommended that you change these values to 256 M and 1024 M respectively. This will enhance Oracle Data Integrator performance. Otherwise, Oracle Data Integrator OutOfMemory errors may occur, especially when running memory intensive tasks.

17.2.6 Excel View Requirements Incorrect in User's Guide

In Oracle Fusion Middleware User's Guide for Oracle Business Activity Monitoring, Chapter 4 Creating and Using Views," section titled "Introduction to the Excel View," the statement "You must have Microsoft Excel 2003 or later to use this feature" is incorrect. Refer to Section 17.1.1, "Oracle BAM Client System Requirements" for Microsoft Excel requirements for using the Oracle BAM Excel view.

17.2.7 Online Help Topic on Filter Comparison Expressions is Empty

This topic should contain navigation links to a list of filter comparison expressions that are presented in the Comparison drop-down list. Click Next in the help viewer to see the correct topic.