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Resource shortage in MQ queue manager in Linux when running large number of clients - additional kernel parameters

Question & Answer


Question

You are running a large number of clients against an MQ queue manager and you want to know why there are FDC files showing resource shortage: probeid XC035040 from pthread_create.
An example of the FDC is:
| Probe Id :- XC035040
| Component :- xcsCreateThread
| Program Name :- amqrmppa
| Major Errorcode :- xecF_E_UNEXPECTED_SYSTEM_RC
| Probe Description :- AMQ6119: An internal WebSphere MQ error has occurred
| ('11 - Resource temporarily unavailable' from pthread_create.)
| Arith1 :- 11 (0xb) | Comment1 :- '11 - Resource temporarily unavailable' from | pthread_create.
.
And it might be followed by:
| Probe Id :- ZS401010
| Component :- zstStartAsyncConsumeThread
| Major Errorcode :- xecP_E_PROC_LIMIT
| Probe Description :- AMQ6026: A resource shortage prevented the creation of a WebSphere MQ process.

Answer

The following page from the MQ documentation has more details on some kernel parameters that can be tuned:
.
https://www.ibm.com/support/knowledgecenter/SSFKSJ_9.1.0/com.ibm.mq.ins.doc/q008550_.htm
IBM MQ 9.1.x / IBM MQ / Installing and uninstalling / Installing and uninstalling IBM MQ on Linux / Preparing the system on Linux / 
Configuring and tuning the operating system on Linux
.
The minimum configuration for MQ for these resources is as follows:
Name     Kernel-name     Value     Description
shmmni     kernel.shmmni     4096     Maximum number of shared memory segments
shmall     kernel.shmall     2097152 Maximum amount of shared memory (pages)
semmns     kernel.sem     4096     Maximum number of semaphores
semmni     kernel.sem     128     Maximum number of semaphore sets
thrmax     kernel.threads-max     32768 Maximum number of threads
pidmax     kernel.pid_max     32768     Maximum number of process identifiers
.
+ Additional resources
.
http://ibm-messaging.github.io/mqperf/
MQ Performance documents
Repository for MQ related performance documents
.
Performance reports for MQ on distributed platforms from V9.1 onwards are available below.
.
- IBM MQ V9.1 for Linux (x86-64 platform) Performance Report:
    http://ibm-messaging.github.io/mqperf/MQ_for_xLinux_V910_Performance.pdf
    MQ_for_xLinux_V910_Performance.pdf
.
- IBM MQ V9.1 for Windows Performance Report:
    http://ibm-messaging.github.io/mqperf/MQ_for_Windows_V910_Performance.pdf
    MQ_for_Windows_V910_Performance.pdf
.
For reports on versions of distributed MQ prior to V9.1 go to the MQ SupportPac page:
   http://www-01.ibm.com/support/docview.wss?uid=swg27007150
   IBM MQ Family - Performance Reports (For MQ 8.0 and earlier).
.

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Product Synonym

WMQ MQ MQSeries

Document Information

Modified date:
03 February 2020

UID

swg21588655

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