HANA stopped unexpectedly due to the accidental deletion of shared memory lock

Symptom

One of my friend faces a strange problem regarding to the unpacked stop of HANA server after cleaning some files under /tmp directory.

After manual starting the system, HANA will run normal again (version: SPS 09 Rev.95).

In nameserver_hosta….trc, the following error is shown:

[79877]{-1}[-1/-1] 2016-02-24 01:15:07.912168 f NameServer

TREXNameServer.cpp(03342) : shared memory lock

‘/tmp/.hdb_ABC_30_lock’was deleted -> stopping instance ...

[79877]{-1}[-1/-1] 2016-02-24 01:15:10.655484 i Service_Shutdown

transmgmt.cc(06027) : Preparing for TransactionManager shutdown

Analysis

File /tmp/.hdb_<SID>_<instance number>_lock is used by HANA as a shared memory lock. If the file is deleted by chance, the database cannot manage the access of shared memory segment anymore and therefore has to stop accordingly.

For more detailed information, please refer to 1984700 – HANA stopped unexpectedly

If you are using RedHat Enterprise Linux, please take care of tmpwatch which delete files order than sometime.

For HANA <= 09, the shared memory lock file is /tmp/.hdb_<sid>_<inst_id>_lock

For HANA >= 10, the shared memory lock file is /var/lib/hdb/<sid>/.hdb_<sid>_<inst_id>_lock

(1999998 – FAQ: SAP HANA Lock Analysis)

Solution

DO NOT delete shared memory lock file.

If you are running RedHat, please remove tmpwatch from the system’s cron job。

Hope the blog can help you fix the same kind of problem you face. Thanks to Chiwo Lee for experience sharing.

Regards,

Ning