MySQL Bugs: #34596: Incorrect handling of upgrade from <6.3.8 to >= 6.3.8 wrt LCP

Bug #34596	Incorrect handling of upgrade from <6.3.8 to >= 6.3.8 wrt LCP
Submitted:	15 Feb 2008 14:26	Modified:	21 Feb 2008 10:34
Reporter:	Jonas Oreland	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Cluster: Cluster (NDB) storage engine	Severity:	S3 (Non-critical)
Version:		OS:	Any
Assigned to:	Jonas Oreland	CPU Architecture:	Any

Description:
In 6.3.8 the no of saved LCP has been decreased from 3 to 2
Then a node > 6.3.8 started using a filesystem from 6.3.6 it can
incorrectly invalidate the the previous LCP to early during the restart
making it to fail.

How to repeat:
while true; do ~/src/6.3.7/storage/ndb/src/kernel/ndbd --initial ; create_tab T1; ndb_mgm -e "all dump 7017"; sleep 1; eval "hugoFill T1 &"; sleepr 3 15; ndb_mgm -e "all stop"; sleep 3; killall -9 ndbd; ~/src/6.3.7/storage/ndb/src/kernel/ndbd ; ndb_waiter; killall -9 ndbd; ~/src/telco-6.3/storage/ndb/src/kernel/ndbd; ndb_waiter; ndb_mgm -e "all stop -a"; sleep 1; killall -9 ndbd; done

Suggested fix:
wait with update nextLcp variable until sendLCP_FRAG_ORD

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/42449

ChangeSet@1.2876, 2008-02-17 11:37:12+01:00, jonas@perch.ndb.mysql.com +1 -0
  ndb - bug#34596
    1) move updating of nextLcp to sendLCP_FRAG_ORD
    2) change impl. of findStartGci to check all LCPs not
       only take first that looks possible

Documented in the 5.1.23-ndb-6.3.10 changelog as follows:

        Due to the reduction of the number of local checkpoints from 3
        to 2 in MySQL 5.1.23-ndb-6.3.8, a data node using ndbd from
        MySQL 5.1.23-ndb-6.3.8 or later started using a filesystem from
        an earlier version could incorrectly invalidate local
        checkpoints too early during the startup process, causing the
        node to fail.

Left in PP status pending further merges.

pushed to 6.3 (and released)

Already documented for ndb-6.3.10; closed.