Occasionally Reports Server Engine Hangs before/after Connecting to RDBMS - Finally Causing REP-56055 (Doc ID 334754.1)

Last updated on JULY 19, 2023

Applies to:

Symptoms

While running reports, sometimes the report engines hang. When all the engines of the report server hangs this way, new report requests usually fail with the following error:

REP-56055: Exceed max connections allowed: XX

The problem does not always happen. It is not consistent and is not limited to some specific reports. In the systems where the problem occurs, it is observed that the problem reproduce even with the test.rdf report that is shipped with iAS.

Sometimes it is observed that the problem occurs when the reports are run with some specific database connections, but does not reproduce while running reports against a similar but different RDBMS. For example, the TEST RDBMS may work properly, while with the PROD RDBMS, the problem occurs.

In some cases, the parameter " engineResponseTimeOut" workaround and killed the hang sessions which prevented the whole report server to hang, but in one other cases, this parameter did not kill the hung jobs as well where it was necessary to kill the report server and restart to recover from the problem when it occurs.

When tracing is enabled, the last lines before the hang are similar to followings in the engine traces:

[2005/9/8 3:58:34:171] Info 55003 (RWEngine:init): Register this engine to Oracle Reports Server .....
[2005/9/8 3:58:35:171] Debug 50103 (EngineImpl:setCommandLine): Running
[2005/9/8 3:58:35:171] Info 50132 (EngineImpl:setCommandLine): Get command line: baseUrl=......
[2005/9/8 3:58:35:187] Debug 50103 (EngineImpl:setCommandLine): Quit
[2005/9/8 3:59:7:218] Debug 50103 (EngineImpl:run): Running

Normally, after these lines you would get a trace similar to following which shows the sqlnet RDBMS connection:

[2005/9/8 3:59:7:219] (C Engine)       Logged onto server: XXXX
[2005/9/8 3:59:7:220] (C Engine)       Username: USERNAME
[2005/9/8 3:59:7:221] (C Engine)

There had been cases reported hanging report requests  BOTH before AND after this trace information in trace files.

If you observe a similar trace information, then it is possible that you are being affected by the problem described in this document.

Cause

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