Reduce number of history requests to database.

[kvaps]

Enhancement Request

Description

Hi I just found that i have a lot requests to my database like:

SELECT body FROM history WHERE vid = 1234 AND seq = 200;
SELECT body FROM history WHERE vid = 1234 AND seq = 199;
SELECT body FROM history WHERE vid = 1234 AND seq = 198;
SELECT body FROM history WHERE vid = 1234 AND seq = 197;
SELECT body FROM history WHERE vid = 1234 AND seq = 196;
...

I not understand why just not use:

SELECT body FROM history WHERE vid = 1234 AND seq <= 200;

Use case

Only one request instead of many will greatly increase the productivity of operations.
It should bring more performance for db connection with less load.

Progress Status

• Branch created
• Code committed to development branch
• Testing - QA
• Documentation
• Release notes - resolved issues, compatibility, known issues
• Code committed to upstream release/hotfix branches
• Documentation committed to upstream release/hotfix branches

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. The OpenNebula Dev Team

[kvaps]

up

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. The OpenNebula Dev Team

[stale]

This issue has been automatically closed due to lack of activity/feedback. Please reopen if you have further input or need to bump this. The OpenNebula Dev Team

[paczerny]

Not only that we use slow method to read the history, but we read it very often. E.g. for onevm undeploy we read all history records 9 times :-(

Possible improvements:

• use SELECT body FROM history WHERE vid = 1234 AND seq <= 200; to read history here
• Do some kind of lazy loading of history records, we usually don't need them, load just last 2 records. Use explicit call to load all records when needed
• Review code for subsequent calls of vm_pool->get or vm_pool->get_ro. basic_authorization method is a good candidate by replacing the first parameter id by pointer to object.