Bug #11459 ndb status variables not updated
Submitted: 20 Jun 2005 13:43 Modified: 4 Jul 2006 4:39
Reporter: Stewart Smith Email Updates:
Status: Closed Impact on me:
Category:MySQL Cluster: Cluster (NDB) storage engine Severity:S3 (Non-critical)
Version:5.0.7 OS:
Assigned to: Stewart Smith CPU Architecture:Any

[20 Jun 2005 13:43] Stewart Smith
NDB status variables are not updated.

for example, when mgm servers change.

How to repeat:
start cluster (with 1/2 mgm nodes)
start mysqld
stop cluster
start cluster with different management node being active
examine variables

Suggested fix:
call update_status_variables in ha_ndbcluster.cc when things change.

Also have complete connectstring as a variable.
[26 Jun 2006 4:46] Stewart Smith
It's interesting (read: good) that these status variables
aren't documented.

However, the main problem with them is not that they're not updated, but that they're named poorly.

We're not reporting connected host and port at all. We're reporting the management server we first connected to which we fetched the configuration from. This is probably more valuable than which management servers we can currently contact (this should possibly be reported elsewhere - but isn't).

The other variables: node id and number of storage nodes both cannot change while the mysql server is up, so there is no problem in not updating these either.

If we do want real status information, we should add variables/tables with this information.

I propose a patch similar to the following:
===== sql/ha_ndbcluster.cc 1.262 vs edited =====
--- 1.262/sql/ha_ndbcluster.cc  2006-06-21 17:50:32 +10:00
+++ edited/sql/ha_ndbcluster.cc 2006-06-23 16:52:18 +10:00
@@ -160,8 +160,8 @@

 struct show_var_st ndb_status_variables[]= {
   {"cluster_node_id",        (char*) &ndb_cluster_node_id,         SHOW_LONG},
-  {"connected_host",         (char*) &ndb_connected_host,      SHOW_CHAR_PTR},
-  {"connected_port",         (char*) &ndb_connected_port,          SHOW_LONG},
+  {"config_from_host",         (char*) &ndb_connected_host,      SHOW_CHAR_PTR},
+  {"config_from_port",         (char*) &ndb_connected_port,          SHOW_LONG},
 //  {"number_of_replicas",     (char*) &ndb_number_of_replicas,      SHOW_LONG},
   {"number_of_storage_nodes",(char*) &ndb_number_of_storage_nodes, SHOW_LONG},
   {NullS, NullS, SHOW_LONG}
[26 Jun 2006 13:31] Bugs System
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:

[26 Jun 2006 13:33] Stewart Smith
tomas approved
[28 Jun 2006 12:30] Stewart Smith
pushed to team trees 4.1, 5.0 and 5.1
[29 Jun 2006 9:51] Tomas Ulin
pushed to 5.1.12
[29 Jun 2006 12:04] Stewart Smith
Pushed to 5.0.23 and 5.1.12
[4 Jul 2006 4:39] Jon Stephens
Documented bugfix in 5.0.23/5.1.12 changelogs.

Documented NDB status variables in Manual.


Verified with Stewart that this push doesn't affect 4.1 (status variables aren't supported before 5.0).