Slow log in due to mysql query [closed]

Question

We want to migrate from OCS 2.8 on CentOS8 to OCS 2.9.2 on RHEL8.5, all is ok except a very slow log in.

On the new server, when we log in, mysql use 100% CPU  for around 30 sec, executing the following query:

SELECT DISTINCT n.netid as ipsubnet,s.name,s.id  FROM netmap n LEFT JOIN subnet s ON s.netid=n.netid ,accountinfo a WHERE (s.TAG IS NULL OR s.TAG = '') union select netid,name,id from subnet WHERE TAG IS NULL OR TAG = ''

The same query is not executed on the old server. The query time execution is equal between the old and the new server.

Regards,

Cybercanto.

Answer 1

Got the same problem after upgrading from 2.8.1 to 2.9.2 (Ubuntu 18.04.5 LTS)

Query take 20sec

Answer 2

Log in goes fast again after delete netmap table data.

Netmap table contained  52062 rows.

New setting IPDISCOVER_PURGE_OLD was in off state, perhaps it will purge himself now.