Troubleshooting
Problem
The server can show a delayed response during the run of some processes/operations and may entirely fail to respond.
Symptom
That performance degradation might not be reported in the server activity log, especially in case of successful completion of the process or operation. However, many errors similar to the following could be logged in the DB2diag.log during the observed slow performance:
2019-10-16-10.04.23.434865-420 E45750976E605 LEVEL: Severe PID : 18188 TID : 140737352435584 PROC : db2dart INSTANCE: tsminst1 NODE : 000 HOSTNAME: nas.s02554.us.wal-mart.com FUNCTION: DB2 UDB, buffer pool services, sqlbCheckRegistryAndBpvars, probe:10 DATA #1 : <preformatted> WARNING: The user per process file descriptor limit of 4096 is less than the maxfilop setting of 61440. Decrease maxfilop to below the user process file descriptor limit, or increase the user process file descriptor limit to remove this warning. Setting maxfilop temporarily to 3277 2019-10-16-10.04.24.473861-420 E45751582E605 LEVEL: Severe PID : 18223 TID : 140737352435584 PROC : db2dart INSTANCE: tsminst1 NODE : 000 HOSTNAME: nas.s02554.us.wal-mart.com FUNCTION: DB2 UDB, buffer pool services, sqlbCheckRegistryAndBpvars, probe:10 DATA #1 : <preformatted> WARNING: The user per process file descriptor limit of 4096 is less than the maxfilop setting of 61440. Decrease maxfilop to below the user process file descriptor limit, or increase the user process file descriptor limit to remove this warning. Setting maxfilop temporarily to 3277 2019-10-16-10.04.25.557146-420 E45752188E605 LEVEL: Severe PID : 18257 TID : 140737352435584 PROC : db2dart INSTANCE: tsminst1 NODE : 000 HOSTNAME: nas.s02554.us.wal-mart.com FUNCTION: DB2 UDB, buffer pool services, sqlbCheckRegistryAndBpvars, probe:10 DATA #1 : <preformatted> WARNING: The user per process file descriptor limit of 4096 is less than the maxfilop setting of 61440. Decrease maxfilop to below the user process file descriptor limit, or increase the user process file descriptor limit to remove this warning. Setting maxfilop temporarily to 3277
'maxfilop' - Maximum database files open per database. This parameter specifies the maximum number of file handles that can be open per database. If opening a file causes this value to be exceeded, some files in use by the database are closed, the additional processing time of opening and closing files will become excessive and might degrade performance.
Cause
Resolving The Problem
Checking the ulimit for the number of file handles, which is usually set too low by default and verifying that user limits are matching the server requirements.
- In order to know the required access rights and user limits for the server instance, please click here.
- Checking the current limits (in order to verify and update the current user limits, please make sure to run the following commands as instance owner ID. That makes you verify the current instance owner limits and when you update it, the update will be valid for that server instance):
'ulimit -a' command will print the list of current limitations for the current session. The interesting one here will be 'nofile(s)'. as any server started will by default inherit these limits. for example:
# ulimit -a
file(blocks) unlimited
data(kbytes) unlimited
stack(kbytes) 32768
memory(kbytes) 32768
coredump(blocks) 2097151
nofiles(descriptors) 2000
threads(per process) unlimited
processes(per user) unlimited
- In case the limit is not matching the server requirements, you should increase it as follows:
Document Location
Worldwide
Historical Number
TS002872157
Product Synonym
TSM;IBM Spectrum Protect;Tivoli Storage Manager;ITSM;ADSM
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Document Information
Modified date:
03 April 2020
UID
ibm11096570