What steps will reproduce the problem?
1. Use mod_pep (+ variant in 0.11+)
2. Have a few PEP nodes
3. Receive presence from contacts
What is the expected output?
Should be fast and efficient.
What do you see instead?
Lots of storage requests, very slow.
What version of the product are you using?
Please provide any additional information below.
When receiving presence from contacts, mod_pep updates their subscriptions based on caps / disco#info.
Each time it adds or removes a subscription, the node configuration is saved (but presence based subscriptions are filtered out), so generally the existing data is simply replaced with identical data.
In summary: O(n) storage accesses for no reason.