Bug 1349111

Description of problem:

The purge_deleted function of heat-manage does not clean up raw_template entries that are no longer referenced by the stack table (fields: raw_template_id or prev_raw_template_id).

OSP Director deployments creates unreferenced raw_template entries and they continue to build up over time causing this table to potentially consume significant space.

Looking at the code, the current purge_deleted function only operates on raw_template IDs that are being purged from the stack table.

Here is an example SQL that will find these unreferenced entries:

SELECT x_id AS Abandoned_Raw_Template_IDs
FROM
  (SELECT a.id AS x_id
   FROM raw_template a 
   LEFT JOIN stack b 
   ON (a.id = b.raw_template_id)
   WHERE b.raw_template_id IS NULL) AS x,
  (SELECT a.id AS y_id
   FROM raw_template a 
   LEFT JOIN stack b 
   ON (a.id = b.prev_raw_template_id)
   WHERE b.prev_raw_template_id IS NULL) AS y
WHERE x.x_id = y.y_id;


Version-Release number of selected component (if applicable):

openstack-heat-common-5.0.1-6.el7ost.noarch

How reproducible:
100%

Steps to Reproduce:
1. On a fresh OSP-d undercloud; deploy a test overcloud.
2. Delete the overcloud heat stack.
3. Wait >1 min after stack delete completes.
4. Run:  sudo heat-manage purge_deleted -g minutes 1
5. Verify from the database that the stack table is empty but entries remain in the raw_template table:
  select count(1) from stack;
  select count(1) from raw_template;
6. These entries will continue to build up as the Overcloud stack is redeployed or updated.

Actual results:

raw_template table grows over time as Overcloud stack is redeployed or updated.

Expected results:

unreferenced raw_template IDs are purged.

Additional info:

Quick test showing the details:

Prior to the deployment we have zero entries in stack and raw_template table:

$ echo 'select count(1) from stack' |sudo mysql heat
count(1)
0

$ echo 'select count(1) from raw_template' |sudo mysql heat
count(1)
0

Deploy & delete overcloud

$ openstack overcloud deploy \
....

$ heat stack-delete overcloud

Wait at least 1 min

Verify the number of entries in stack and raw_template tables:

$ echo 'select count(1) from stack' |sudo mysql heat
count(1)
168
$ echo 'select count(1) from raw_template' |sudo mysql heat
count(1)
262

Use the SQL from above to get the number of unreferenced raw_template IDs

$ echo 'SELECT count(x_id) AS Abandoned_Raw_IDs_count
FROM
  (SELECT a.id AS x_id
   FROM raw_template a 
   LEFT JOIN stack b 
   ON (a.id = b.raw_template_id)
   WHERE b.raw_template_id IS NULL) AS x,
  (SELECT a.id AS y_id
   FROM raw_template a 
   LEFT JOIN stack b 
   ON (a.id = b.prev_raw_template_id)
   WHERE b.prev_raw_template_id IS NULL) AS y
WHERE x.x_id = y.y_id' |sudo mysql heat

Abandoned_Raw_IDs_count
47

Run the purge_deleted function
 
$ sudo /bin/heat-manage purge_deleted -g minutes 1 

List remaining counts from stack and raw_template tables to show the 47 abandoned entries remain.

$ echo 'select count(1) from stack' |sudo mysql heat
count(1)
0

$ echo 'select count(1) from raw_template' |sudo mysql heat
count(1)
47