[TS-2931] plugin metrics fail after a crash

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.2.2, 5.1.0
• Component/s: Plugins, TS API
• Assignee: James Peach
• Reporter: James Peach
• Created: 09/Jul/14 20:18
• Updated: 18/Dec/14 05:11
• Resolved: 10/Jul/14 00:28

Description

If a plugin uses TSStatFindName followed by TSStatCreate, TSStatFindName can return 0 for all the metric IDs after a traffic_server crash.

AFAICT this will happen every time with the following conditions:
1. traffic_manager has pulled the plugin stat records from traffic_server
2. traffic_server crashes

When traffic_server comes back up, it pulls the records from traffic_manager. traffic_manager sends the records including the rsb_id field. However, RecForceInsert() does not copy the rsb_id field from the message to the actual record. There are 2 reasonable fixes:

• We could not propagate the 'registered' flag for records that we on. This forces the code to re-register, which will bring the stats back to the correct state.
• We could ensure that we copy the rsb_id field so that stat lookups succeed.