Bug #50621 Increase ndb_autoincrement_prefetch_sz to >256
Submitted: 26 Jan 2010 12:49 Modified: 28 Jan 2010 9:26
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-telco-6.3 OS:Any
Assigned to: Jonas Oreland
Tags: autoincrement
Triage: Triaged: D5 (Feature request) / R2 (Low) / E2 (Low)

[26 Jan 2010 12:49] Johan Andersson
Description:
Max of ndb_autoincrement_prefetch_sz is 256.

How to repeat:
..

Suggested fix:
Changing it to more is trivial:

in mysqld.cc:

  {"ndb-autoincrement-prefetch-sz", OPT_NDB_AUTOINCREMENT_PREFETCH_SZ,
   "Specify number of autoincrement values that are prefetched.",
   (uchar**) &global_system_variables.ndb_autoincrement_prefetch_sz,
   (uchar**) &max_system_variables.ndb_autoincrement_prefetch_sz,
   0, GET_ULONG, REQUIRED_ARG, 1, 1, 256, 0, 0, 0},

change to 

  {"ndb-autoincrement-prefetch-sz", OPT_NDB_AUTOINCREMENT_PREFETCH_SZ,
   "Specify number of autoincrement values that are prefetched.",
   (uchar**) &global_system_variables.ndb_autoincrement_prefetch_sz,
   (uchar**) &max_system_variables.ndb_autoincrement_prefetch_sz,
   0, GET_ULONG, REQUIRED_ARG, 1, 1, 65535, 0, 0, 0},
[27 Jan 2010 13:38] 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/98336

3094 Jonas Oreland	2010-01-27
      ndb - bug#50621 - allow autoincrement prefetch size up to 65536
[27 Jan 2010 13:49] Jonas Oreland
pushed to 6.3.31 and 7.0.11
increased max to 65536
[28 Jan 2010 9:26] Jon Stephens
Documented feature change in the NDB-6.3.31 and 7.0.11 changelogs as follows:

        The maximum allowed value of the 
        ndb_autoincrement_prefetch_sz variable has been increased 
        from 256 to 65536.

Also noted change at http://dev.mysql.com/doc/refman/5.1/en/mysql-cluster-system-variables.html#sysvar_ndb_auto....

Closed.