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Monitoring error messages uc.png

Authors: KathrynFryer, TimFeeney
Build basis: Rational Collaborative Lifecycle Management (CLM) and Watson Internet of Things Continuous Engineering (IoTCE) solutions 6.0.2

As part of their monitoring strategy for the CLM or IoTCE solution, some clients opt to use third-party tools to parse and monitor messages logged in log files to identify issues or potential issues. If you choose to monitor the logs, this page describes some messages and scenarios to watch for. The list provided here is intended as a starting point; over time, you might choose to add or remove messages from your "watch list" based on your experience. If the log file is not specifically identified, the message could appear in any of the CLM/CE application logs.

Out-of-memory errors

Look for the text OutOfMemoryError, as well as Native Memory and Java Heap.

Native memory is the memory reserved for the classes. When you include compressedrefs in the JVM settings, native memory is the first 4G of memory reserved. If you continue to see native out-of-memory errors, you might need more than that 4G reserve, and switch to the nocompressedrefs setting.

For out-of-memory errors in general, you can look at the verbose garbage collection logs to see when memory started to increase, and then examine the application logs or a thread dump for that time period to see what was happening. You could use a tool like IBM Memory Analyzer to drill into the heap dump to find leak suspects and classes consuming the most memory.

Java dumps

In the WebSphere Application Server (WAS) native_stderr.log, JVMDUMP032I is logged any time a Java dump is requested, including thread dump, system dump, and memory dump. JVMDUMP030W is logged if the dump cannot be written, which could be due to issues with permissions, disk space, or another reason.

Because users can trigger dumps with various tools and from the WAS console, you probably do not want to monitor all the JVMDUMP messages, which are documented in this topic in the IBM Knowledge Center. Over time, you might add selected messages to your watch list based on your experience. You would need to analyze the dump to determine the root cause and take action accordingly.

Long-running threads

Look in the WAS Systemout.log file for the text thread(s) in total in the server that may be hung, or alternatively WSVR0605W and WSVR0606W. WSVR0605W is generated if a thread runs longer than the time set in WebSphere Application Server (the default is 10 minutes). In some cases, these alerts simply identify jobs that require more time to complete; they indicate what's happening in your system and can identify operations that impact performance. A second message WSVR0606W is generated when the thread completes. When you suspect problems, you can configure WAS to generate a javacore or thread dump when this message occurs, as described in this support article.

For reference, the message text appears as follows:

  • WSVR0605W Thread {threadname} has been active for {time} and may be hung. There are {totalthreads} in total in the server that may be hung.
  • WSVR0606W Thread {threadname{ was previously reported to be hung but has completed. It was active for approximately {time}. There is/are {n} thread(s) in total in the server that still may be hung.

Long-running queries in RM

In the RM log, warning message CRJZS5819W or CRJZS5820W is logged when a query (to return a view or artifacts, for example) runs longer than the threshold setting. Another message CRJZS5742W is logged when the query completes. The threshold value is set in the RM Administration Advanced Properties > Jena query operation logging time threshold (in ms).

The default query threshold is 45 seconds, so not every instance of the warning message indicates an issue. However, if you find multiple sequential instances the same query id, especially without any completion message, you could note the query id and investigate the cause. You cannot stop the query while it is still running.

The full message text appears as follows:

  • CRJZS5819W Query {id} is still running after {n} seconds and has now exceeded the maximum amount of time allowed by the server. This query may be jeopardizing the memory and CPU health of the server. It has {x} user contexts: {contexts}
  • CRJZS5820W Query {id} is still running after {n} seconds and has now exceeded the maximum amount of time allowed by the server. This query may be jeopardizing the memory and CPU health of the server. It is scoped to {scope} and has {x} user contexts: {context}
  • CRJZS5742W Query {id} had an execution time of {n} ms, and produced {x} results

SocketTimeoutException occurrences

Look for the text SocketTimeoutException. This exception indicates that something has taken longer than one of the many configurable socket timeouts set throughout the stack. The exception might indicate an abnormally long running operation, network or server availability issues, or other problem. Use the messages occurring around the exception to determine the potential cause for the timeout. Call Support if you cannot resolve the problem.

A SocketTimeoutException is logged as a Java exception, resembling the following format:

    Caused by: java.net.SocketTimeoutException

SqlTimeoutException occurrences

Look for the text sqlTimeoutException. This error indicates that a JDBC timeout has been reached and the database did not return the result. There are a number of possible causes; use the messages around the exception to investigate the cause.

the error typically resembles the following format:

    Caused by: com.ibm.db2.jcc.am.SqlTimeoutException: DB2 SQL Error: SQLCode = -{code}, SQLSTATE={code}, SQLERRMC={error}

SQLException occurrences

SQL exceptions typically indicate a bad database state, corrupt indexes, data integrity issues, or similar issue. Look for the text SQLException. You would need to investigate the details of the exception.

Corrupt indices

The CLM/CE applications rely on various indices stored in the file system, including Jena, test, and query indices. These indices can get corrupted by incorrect server shutdown, lack of disk space, inability to write to disk, or other reasons. Corrupt indices can cause unexpected application behavior and query results, including missing data. Look for messages with the text indexing and review the other messages in the log to determine the cause.

To address corrupt indices, reindex using the appropriate repotools command for the type of index; see the Repository tools command-line reference topic in the IBM Knowledge Center.

Connection or handshake failures

Connection failures could occur when a new server is added, a certificate expires, or other reasons. These messages are often more of a troubleshooting aid, but could indicate problems. Message text to watch for includes unable to connect, connection refused, connection timed out, and handshake. Similarly, an inability to connect to the database could indicate high server loads, underpowered database server, or other issues. Watch for message CRRGW7022E A connection to the database "{0}" could not be acquired in {1} ms.

Related topics: Deployment web home, Deployment web home

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