IBM Support

Local DB2 connections may hang on operating system semop() operations on RHEL (or CentOS) 6.6 Linux distrubutions

Troubleshooting


Problem

RHEL or CentOS 6.6 (first seen in kernel level 2.6.32-434.el6) contains a semaphore release defect which may cause DB2 connections to hang when the client and server reside on the same host. Remote connections (i.e. through TCPIP) are not susceptible.

Symptom

DB2 connections may hang. If a stack is generated from the application process using gstack, the the stack will show the semop() function at the top.

semop
sqloSSemP
sqlccipcrecv
sqlccrecv
sqljcReceive
sqljrReceive

[{"Product":{"code":"SSEPGG","label":"Db2 for Linux, UNIX and Windows"},"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Component":"Operating System \/ Hardware - Other OS\/Hardware","Platform":[{"code":"PF016","label":"Linux"}],"Version":"9.7;9.5;10.1;10.5","Edition":"","Line of Business":{"code":"LOB10","label":"Data and AI"}}]

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Document Information

Modified date:
19 June 2026

UID

swg21691823