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Intermittent Error - 502 Bad gateway, when accessing reports with Prompts

Troubleshooting


Problem

This tech note describes a solution for an intermittent error experienced when running reports with prompts. When trying to run these reports, users sometimes experience an error where there report doesn't load and instead the message "502 Bad Gateway" is shown. Occurs on systems usign load-balancers.

Symptom

Symptoms of the issue:

  1.  Reports sometimes work after clearing the browser cache
  2. Issue is intermittent
  3. Performance of report is also slow
  4. Error doesn't happen when by-passing gateway and using load-balancing URL instead
  5. No recent changes to Gateway servers or configuration

Resolving The Problem

The issue can be resolved by clearing the cache of the application server from the Administration portal.

  1. In IBM Cognos Administration, on the Configuration tab, click Query Service Caching.
  2. Select the server groups for cache clearing.
  3. Click Clear cache.

    The status of the Clear cache command is displayed.

    If a cache is being used by one or more pending reports or queries, it is internally flagged as "stale" by this command and is automatically cleared as soon as this usage completes.

  4. Click Close.

Related Information

Clear everything in the cache

[{"Business Unit":{"code":"BU059","label":"IBM Software w\/o TPS"},"Product":{"code":"SSTSF6","label":"IBM Cognos Analytics"},"Component":"","Platform":[{"code":"PF002","label":"AIX"},{"code":"PF016","label":"Linux"},{"code":"PF033","label":"Windows"}],"Version":"11.0.x","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

Document Information

Modified date:
28 November 2018

UID

ibm10742707

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