Fixes are available
IBM Tivoli Monitoring: Linux(R) OS Agent 6.2.3.4-TIV-ITM_LINUX-IF0001
IBM Tivoli Monitoring: Linux(R) OS Agent 6.3.0.6-TIV-ITM_LINUX-IF0001
IBM Tivoli Monitoring: Linux(R) OS Agent 6.2.3.3-TIV-ITM_LINUX-IF0007
IBM Tivoli Monitoring 6.3.0 Fix Pack 7 (6.3.0-TIV-ITM-FP0007)
IBM Tivoli Monitoring: Linux(R) OS Agent 6.2.3.5-TIV-ITM_LINUX-IF0002
IBM Tivoli Monitoring: Linux(R) OS Agent 6.3.0.5-TIV-ITM_LINUX-IF0002
APAR status
Closed as program error.
Error description
REL: Linux OS Agent 6.30 FP5 IF01 Problem: Due to a lack of synchronization with the internal thread that collects data for the "Disk Usage Trends" attribute group it may happen that the agent crashes while responding to a query or a situation on the "Linux Disk" attribute group, as the two groups share the same object. The event is rare because the "Disk Usage Trends" thread runs only once per hour by default. Affected Platforms / Versions: This issue may affect all the Linux OS agent versions since 6.30 FP5 IF1 Diagnostics: *** glibc detected *** /opt/IBM/ITM//lx8266/lz/bin/klzagent: double free or corruption (fasttop): 0x00002b24801c2570 *** ======= Backtrace: ========= /lib64/libc.so.6(+0x75e66)[0x2b24617f4e66] /usr/lib64/libstdc++.so.6(_ZNSsD1Ev+0x39)[0x2b246107b4c9] /opt/IBM/ITM//lx8266/lz/bin/klzagent(_ZN7CmntentD1Ev+0x44)[0x52e f38] /opt/IBM/ITM//lx8266/lz/bin/klzagent(_ZSt8_DestroyI7CmntentEvPT_ +0x15)[0x531199] /opt/IBM/ITM//lx8266/lz/bin/klzagent(_ZSt13__destroy_auxIN9__gnu _cxx17__ normal_iteratorIP7CmntentSt6vectorIS2_SaIS2_EEEEEvT_S8_12__false _type+0x32)[0x53138a] Additional Keywords: IV71612 Disk Disk Trends 6.30.05.01 KLZ_DISK_SAMPLE_HRS
Local fix
Increase the value of KLZ_DISK_SAMPLE_HRS to reduce the possibility of memory corruption
Problem summary
Monitoring Agent for Linux OS randomly hangs during Disk data collection. Due to a lack of synchronization with the internal thread that collects data for the "Disk Usage Trends" attribute group it may happen that the agent hangs while responding to a query or a situation on the "Linux Disk" attribute group, as the two groups share the same object. The event is rare because the "Disk Usage Trends" thread runs only once per hour by default.
Problem conclusion
Made mutex recursive and introduced the lock/unlock pair in any calls coming from the two attribute groups. The fix for this APAR is included in the following maintenance vehicle: | fix pack | 6.3.0-TIV-ITM-FP0007 | | interim fix | 6.3.0.5-TIV-ITM_LINUX-IF0002 | | interim fix | 6.3.0.6-TIV-ITM_LINUX-IF0001 |
Temporary fix
Set the environment variable KLZ_DISK_SAMPLE_HRS to a very large number of seconds in order to reduce the likelihood of this rare condition. For example KLZ_DISK_SAMPLE_HRS=86400 set the frequency of the "Disk Usage Trends" thread at 1 day.
Comments
APAR Information
APAR number
IV78033
Reported component name
ITM AGENT LINUX
Reported component ID
5724C04LN
Reported release
630
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2015-10-14
Closed date
2015-10-29
Last modified date
2017-01-06
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
ITM AGENT LINUX
Fixed component ID
5724C04LN
Applicable component levels
R630 PSY
UP
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Document Information
Modified date:
06 January 2017