MySQL Bugs: #42015: ndb_mgmd --initial + no config file = hang

Bug #42015	ndb_mgmd --initial + no config file = hang
Submitted:	10 Jan 2009 15:35	Modified:	28 Sep 2009 14:29
Reporter:	Jon Stephens	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Cluster: Cluster (NDB) storage engine	Severity:	S3 (Non-critical)
Version:	mysql-5.1-telco-7.0	OS:	Any
Assigned to:	Magnus Blåudd	CPU Architecture:	Any
Tags:	--config-file, --initial, 5.1.30-ndb-6.4.1-bzr, ndb_mgmd

Description:
If you start the management server with the --initial option and it cannot find a configuration file, it deletes all cache files and then hangs.

Same thing happens if there's no cache and no config.ini; the management server just waits forever AFAICT.

How to repeat:
jon@tonfisk:~/bin/mysql-5.1-telco-6.4/libexec> ./ndb_mgmd --initial
2009-01-10 15:57:39 [MgmSrvr] INFO     -- NDB Cluster Management Server. mysql-5.1.30 ndb-6.4.1-beta
2009-01-10 15:57:39 [MgmSrvr] INFO     -- Trying to get configuration from other mgmd(s) using 'nodeid=0,localhost:1186'...

(Ten minutes later...)
<^C>
jon@tonfisk:~/bin/mysql-5.1-telco-6.4/libexec>

Suggested fix:
If the management server isn't going to check for a config.ini before deleting the cache files, then there should be a timeout - IMO ten seconds is more than enough time - after which it should exit with a "No configuration found" error message.

However, this is sort of a nasty trick to play on users, and a better solution might be for ndb_mgmd to check for a config.ini *before* wiping out the cache, and if none is found, exiting instead.

In any case, it shouldn't just do the sit-and-spin bit forever...

Wrote a patch that makes a ndbg_mgmd that is trying to connect to another ndb_mgmd print out a message about this approx. every 30 second.

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/84586

Pushed to 7.0 and 7.1

Documented bugfix in the NDB-7.0.8 changelog as follows:

        When started with the --initial and --reload options, if
        ndb_mgmd could not find a configuration file or connect to
        another management server, it appeared to hang. Now, when trying
        to fetch its configuration from another management node,
        ndb_mgmd checks and signals (Trying to get configuration from
        other mgmd(s)) each 30 seconds that it has not yet done so.

Closed.

Pushed into 5.1.37-ndb-7.0.9 (revid:jonas@mysql.com-20090930075942-1q6asjcp0gaeynmj) (version source revid:magnus.blaudd@sun.com-20090925104247-ozlmf4vu1f3936am) (merge vers: 5.1.37-ndb-7.0.8) (pib:11)

Pushed into 5.1.35-ndb-7.1.0 (revid:jonas@mysql.com-20090930080049-1c8a8cio9qgvhq35) (version source revid:jonas@mysql.com-20090925143824-3i5kcvsf8v3yf79j) (merge vers: 5.1.35-ndb-7.1.0) (pib:11)