MySQL Bugs: #49894: shifted MYSQL_REPLICATION

Bug #49894	shifted MYSQL_REPLICATION_PLUGIN number
Submitted:	23 Dec 2009 15:21	Modified:	7 Mar 2010 1:22
Reporter:	Sergei Golubchik	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Replication	Severity:	S3 (Non-critical)
Version:	5.5-m2	OS:	Any
Assigned to:	Zhenxing He	CPU Architecture:	Any

Description:
in 6.0:

#define MYSQL_INFORMATION_SCHEMA_PLUGIN  4  /* The I_S plugin type */
#define MYSQL_AUDIT_PLUGIN           5  /* The Audit plugin type        */
#define MYSQL_REPLICATION_PLUGIN     6	/* The replication plugin type */
#define MYSQL_MAX_PLUGIN_TYPE_NUM    7  /* The number of plugin types   */

in next-mr:

#define MYSQL_INFORMATION_SCHEMA_PLUGIN  4  /* The I_S plugin type */
#define MYSQL_REPLICATION_PLUGIN     5	/* The replication plugin type */
#define MYSQL_MAX_PLUGIN_TYPE_NUM    6  /* The number of plugin types   */

that is replication plugin is number 6 in 6.0 and number 5 in next-mr.
it breaks the whole idea of plugins - one cannot load replication plugin both into 6.0 and next-mr, and audit plugin when loaded into next-mr will be wrongly recognized as replication plugin.

How to repeat:
.

Suggested fix:
Possible solutions

1. backport audit plugin into next-mr

2. backport only the define MYSQL_AUDIT_PLUGIN 5 and add few lines to sql_plugin.cc that will say "audit plugins are not supported" when one tries to load it.

3. swap plugin numbers for replication and audit in 6.0 - this is the most simple change, but, being an incompatible ABI change, it requires MYSQL_PLUGIN_INTERFACE_VERSION to be increased (to 0x2000) which automatically invalidates *all* plugins of *all* types.

Thank you for the bug report.

For this particular case, I think that solution number 2 suggested by Serg has the smallest risk is the cleanest solution. It does not require invalidation of any plug-ins nor does it require extensive work to backport the audit plug-in.

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/98429

3127 He Zhenxing	2010-01-28
      Bug#49894 shifted MYSQL_REPLICATION_PLUGIN number
      
      The number for MYSQL_REPLICATION_PLUGIN was shifted when backporting
      because MYSQL_AUDIT_PLUGIN was not backported.
      
      This problem is fixed by backporting only the number of audit plugin
      and print an error when trying to load audit plugins. Note that
      replication plugins compiled against old MYSQL_REPLICATION_PLUGIN
      number will also be recognized as audit plugin and be rejected. 
     @ include/mysql/plugin.h
        backporting the number of audit plugin (MYSQL_AUDIT_PLUGIN)
     @ sql/sql_plugin.cc
        backporting the number of audit plugin (MYSQL_AUDIT_PLUGIN)
        print an error when trying to load audit plugins

Hi Zhenxing,
  Isn't this already fixed in next-mr after revision:
  svoj@sun.com-20100122083751-x2lhrzwzzqgzx6m6

Looking at include/mysql/plugin.h in revision
alik@sun.com-20100125161225-mpr7xlu4kvx45e1i

I see: 

#define MYSQL_AUDIT_PLUGIN           5  /* The Audit plugin type        */
#define MYSQL_REPLICATION_PLUGIN     6  /* The replication plugin type */
#define MYSQL_MAX_PLUGIN_TYPE_NUM    7  /* The number of plugin types   */

Looks like this has already been fixed... Can you please confirm?

And by fixed I mean the audit plugin seems backported
(which is option #1 in the list of suggested fixes by 
Sergei).

as Luis said, audit plugin has been backported, so this bug will also be fixed by the backporting.

The patch approved.

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/99194

3127 He Zhenxing	2010-02-04
      Bug#49894 shifted MYSQL_REPLICATION_PLUGIN number
      
      The number for MYSQL_REPLICATION_PLUGIN was shifted when backporting
      because MYSQL_AUDIT_PLUGIN was not backported.
      
      This problem is fixed by backporting only the number of audit plugin
      and print an error when trying to load audit plugins. Note that
      replication plugins compiled against old MYSQL_REPLICATION_PLUGIN
      number will also be recognized as audit plugin and be rejected.
     @ include/mysql/plugin.h
        backporting the number of audit plugin (MYSQL_AUDIT_PLUGIN)
     @ sql/sql_plugin.cc
        backporting the number of audit plugin (MYSQL_AUDIT_PLUGIN)
        print an error when trying to load audit plugins

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/99197

2983 He Zhenxing	2010-02-04 [merge]
      audit plugin has already backported
      Null merge the fix for Bug#49894

Pushed into 5.5.2-m2 (revid:joerg@mysql.com-20100212164100-jnurxdw5z88m472s) (version source revid:joerg@mysql.com-20100212164100-jnurxdw5z88m472s) (merge vers: 5.5.2-m2) (pib:16)

Pushed into 6.0.14-alpha (revid:alik@sun.com-20100213083436-9pesg4h55w1mekxc) (version source revid:luis.soares@sun.com-20100211135109-t63avry9fqpgyh78) (merge vers: 6.0.14-alpha) (pib:16)

Pushed into mysql-next-mr (revid:alik@sun.com-20100213083327-cee4ao3jpg33eggv) (version source revid:luis.soares@sun.com-20100211135018-1f9dbghg0itszigo) (pib:16)

Noted in 5.5.2 changelog.

In plugin.h, the MYSQL_REPLICATION_PLUGIN symbol was out of synchrony
with its value in MySQL 6.0 because the lower-valued
MYSQL_AUDIT_PLUGIN was not present. To correct this,
MYSQL_AUDIT_PLUGIN has been added in MySQL 5.5, changing the value of
MYSQL_REPLICATION_PLUGIN from 5 to 6. Replication plugins from
earlier 5.5.x releases must be recompiled against the current release
before they will work with the current release.

Revised changelog entry:

In plugin.h, the MYSQL_REPLICATION_PLUGIN symbol was out of synchrony
with its value in MySQL 6.0 because the lower-valued
MYSQL_AUDIT_PLUGIN was not present. To correct this,
MYSQL_AUDIT_PLUGIN has been added in MySQL 5.5, changing the value of
MYSQL_REPLICATION_PLUGIN from 5 to 6. Attempts to load the audit
plugin produce an error occurs because only the MYSQL_AUDIT_PLUGIN
symbol was added, not the audit plugin itself. This error will go
away when the audit plugin is added to MySQL 5.5. Replication plugins
from earlier 5.5.x releases must be recompiled against the current
release before they will work with the current release.

Pushed into 5.5.3-m3 (revid:alik@sun.com-20100306103849-hha31z2enhh7jwt3) (version source revid:vvaintroub@mysql.com-20100213160132-nx1vlocxuta76txh) (merge vers: 5.5.99-m3) (pib:16)

Already fixed in earlier 5.5.x.