Field Notice: FN - 72029 - Connection Leak in Cisco BroadWorks Xsi-Events May Cause Excessive Delays in Responses - Software Upgrade Recommended

Notice

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Revision History

Revision	Publish Date	Comments
1.0	08-Feb-21	Initial Release

Products Affected

Affected OS Type	Affected Software Product	Affected Release	Affected Release Number	Comments
NON-IOS	Application Patches	22.0	22.0.2020.02, 22.0.2020.03, 22.0.2020.04, 22.0.2020.05, 22.0.2020.06, 22.0.2020.07, 22.0.2020.08, 22.0.2020.09, 22.0.2020.10, 22.0.2020.11, 22.0.2020.12
NON-IOS	Application Patches	23.0	23.0.2020.02, 23.0.2020.03, 23.0.2020.04, 23.0.2020.05, 23.0.2020.06, 23.0.2020.07, 23.0.2020.08, 23.0.2020.09, 23.0.2020.10, 23.0.2020.11, 23.0.2020.12

Defect Information

Defect ID	Headline
CSCvw75025	BEMS01179708 UC One Sign In Issues

Problem Description

A potential connection leak in the Xsi-Events application upon channel disconnection may cause undue increase in HTTP connection latency when max connections is reached due to requests waiting for resources to become available. The increased latency may cause HTTP requests to fail as timeouts are reached.

Background

The source of the connection leak is related to the rework of the Xsi-Events application to use the non-blocking servlet API instead of the deprecated Comet API. Because the connection pool becomes saturated, new HTTP connections may fail to be established or take a long time to be established, causing HTTP request timeouts. Because the increased latency happens before connections are accepted, the latency is not readily visible or evident in the access logs.

Because of the knock-on effects, other applications hosted on the XSP may also experience degraded performance. The point at which the connection pool becomes saturated is relative to the total resources available to the XSP, meaning that the connection pool may become saturated faster on smaller XSP deployments.

Problem Symptom

There are several indicators of the issue that can be detected:

• The alarm bwHttpWorksBusyExceeded is raised.
• The counter bwHttpWorkerThreadsBusy is high and stays high.
• The counter bwHttpWorkThreadsIdle is low and stays low.
• Presence of the following log in the Xsi-Events logs: Removing Channel (forced).

Associated with the connection leak, there will be an increased number of failed HTTP requests due to timeouts and latency. Restarting the XSP/ADP can temporarily mitigate the issue, but the connection pool will become saturated again over time.

Workaround/Solution

The following Cisco Broadworks patchs must be applied to correct the issues:

Release R22

• AP.xsp.22.0.1123.ap377715

Release R23

• AP.xsp.23.0.1075.ap377715

ADP Releases

• This issue is expected to be patched as a part of the 2021.01 release.

BroadWorks patches can be downloaded through the Cisco Software Download Center after logging in with your Cisco.com (CCO) account.

The version of BroadWorks that is currently deployed as well as the patches currently activated can be checked by executing the get versions all command from the CLI. More information on how to check the patch level can be found in the Cisco BroadWorks Maintenance Guide associated with the release version.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

• Open a service request on Cisco.com
• By email or telephone

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