Bug #33802 ndb_drop table does not release data memory!
Submitted: 10 Jan 2008 16:09 Modified: 25 Apr 2008 8:23
Reporter: Johan Andersson Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Cluster: Cluster (NDB) storage engine Severity:S3 (Non-critical)
Version:mysql 5.1.23 - ndb 6.3.7 OS:Any
Assigned to: Jonas Oreland CPU Architecture:Any

[10 Jan 2008 16:09] Johan Andersson
Description:
I createad a simple table:
create table( a bigint, b integer unsigned not null, c integer unsigned not null, d varchar(255), e varchar(255), key (c), primary key(a)) engine=ndb;

hugoFill to fill it.

Before drop table:
2008-01-10 16:50:30 [MgmSrvr] INFO     -- Node 3: Data usage increased to 90%(172876 32K pages of total 192000)
2008-01-10 16:50:30 [MgmSrvr] INFO     -- Node 2: Data usage increased to 90%(172912 32K pages of total 192000)
2008-01-10 16:37:59 [MgmSrvr] INFO     -- Node 2: Index usage is 4%(5656 8K pages of total 128032)
2008-01-10 16:38:00 [MgmSrvr] INFO     -- Node 3: Index usage is 4%(5659 8K pages of total 128032)

after drop table:
ndb_mgm> Node 2: Data usage is 83%(160298 32K pages of total 192000)
Node 2: Index usage is 0%(16 8K pages of total 128032)
Node 3: Data usage is 83%(160298 32K pages of total 192000)
Node 3: Index usage is 0%(16 8K pages of total 128032)

Hmm.. not all data memory has been released...

How to repeat:
see above

Suggested fix:
-
[11 Jan 2008 10:59] 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:

  http://lists.mysql.com/commits/40901

ChangeSet@1.2836, 2008-01-11 12:00:11+01:00, jonas@perch.ndb.mysql.com +3 -0
  ndb - bug#33802
    full var-pages was not released at drop-table, as they were not on any free-list
    (introduced by page-release push)
[23 Jan 2008 10:00] Jonas Oreland
pushed to telco-63 & telco-64
[1 Feb 2008 14:11] Jon Stephens
Documented fix in 5.1.23-ndb-6.3.8 changelog as follows:

        DROP TABLE did not free all data memory. This
        bug was observed in MySQL 5.1.23-ndb-6.3.7 only.

Left bug in PQ status pending further merges.
[25 Apr 2008 8:23] Jonas Oreland
no further merging
closing