Bug 579810 - Collection of Postgres table metrics fails when the tables are not in the public schema
Summary: Collection of Postgres table metrics fails when the tables are not in the pub...
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: RHQ Project
Classification: Other
Component: Plugins
Version: 1.3.1
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
: RHQ 4.11
Assignee: Thomas Segismont
QA Contact: Mike Foley
URL:
Whiteboard:
Depends On:
Blocks: 1095369
TreeView+ depends on / blocked
 
Reported: 2010-04-06 15:51 UTC by lionel.duriez
Modified: 2014-07-21 10:13 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
: 1095369 (view as bug list)
Environment:
Last Closed: 2014-07-21 10:13:41 UTC
Embargoed:


Attachments (Terms of Use)

Description lionel.duriez 2010-04-06 15:51:41 UTC
The table metrics cannot be collected when the tables do not belong to the public schema.
The problem appears on the following environment :
Monitored Database : Postgresql 8.3
RHQ agent plugin version : rhq-postgres-plugin-1.3.1
Jopr Server version : 2.3.1

To reproduce the problem, create a new schema in a monitored database :
create schema myschema;

Then create a table in the new schema :
create table myschema.mytable (name varchar(20));

In Jopr, no metrics are available for the table mytable.
The role used by the agent to connect to the Postgresql DB is postgres.

The reason for the failure to collect the metrics can be found in the Postgresql logs :

ERROR:  relation "mytable" does not exist
STATEMENT:  SELECT ts.*,  pg_relation_size(ts.relname) AS table_size, pg_total_relation_size(ts.relname) AS total_size,
          ios.heap_blks_read, ios.heap_blks_hit, ios.idx_blks_read, ios.idx_blks_hit,
          ios.toast_blks_read, ios.toast_blks_hit, ios.tidx_blks_read, ios.tidx_blks_hit
        FROM pg_stat_user_tables ts LEFT JOIN pg_statio_user_tables ios on ts.relid = ios.relid
        WHERE ts.relname = $1

This is due to the fact that by default the search_path of a postgresql role is :
"$user",public

By default, the newly created schema is not looked in when performing a query.

To fix the problem, the select statement could me modified to look like this :

SELECT ts.*,
          pg_relation_size(ts.schemaname || '.' || ts.relname) AS table_size,
          pg_total_relation_size(ts.schemaname || '.' || ts.relname) AS total_size,
          ios.heap_blks_read, ios.heap_blks_hit, ios.idx_blks_read, ios.idx_blks_hit,
          ios.toast_blks_read, ios.toast_blks_hit, ios.tidx_blks_read, ios.tidx_blks_hit
        FROM pg_stat_user_tables ts LEFT JOIN pg_statio_user_tables ios on ts.relid = ios.relid
        WHERE ts.relname = 'mytable' and ts.schemaname='myschema';

As a temporary workaround, one could alter the search_path for the role postgres :

alter role postgres set search_path="$user",public,myschema;

Comment 1 Thomas Segismont 2014-04-08 09:59:11 UTC
Fixed in master

commit 835eca6a7b14bc92db5f98d336470f9b6ece145e
Author: Thomas Segismont <tsegismo>
Date:   Tue Apr 8 11:15:14 2014 +0200

Changed resource key format ("tablename"->"schemaname.tablename")
    
Implemented resource upgrade and updated resource component and discovery component
    
Also changed the availability check: new the resource component checks for table existence instead of looking at the parent database availability

Comment 2 Thomas Segismont 2014-04-09 15:47:26 UTC
The fix for this bug is a prerequisite of the fix for Bug 1079403

Comment 3 Heiko W. Rupp 2014-07-21 10:13:41 UTC
Bulk closing of RHQ 4.11 issues, now that RHQ 4.12 is out.

If you find an issue with those, please open a new BZ, linking to the old one.


Note You need to log in before you can comment on or make changes to this bug.