Federation likes (votes) are wildly different from server to server as it stands now. And unless something is way off on my particular server, 0.4 seconds is what PostgreSQL is reporting as the mean (average) time per single comment vote INSERT, and post vote INSERT is similar. (NOTE: my server is classic hard drives, 100MB/sec bencharked, not a SSD)
Discussion of the SQL statement for a single comment vote insert: https://lemmy.ml/post/1446775
Every single VOTE is both a HTTP transaction from the remote server and a SQL transaction. I am looking into Postgress supporting batches of inserts to not check all the index constraints at each single insert: https://www.postgresql.org/docs/current/sql-set-constraints.html
Can the Rust code for inserts from federation be reasonably modified to BEGIN TRANSACTION only every 10th comment_like INSERT and then do a COMMIT of all of them at one time? and possibly a timer that if say 15 seconds passes with no new like entries from remote servers, do a COMMIT to flush based a timeout.
Storage I/O writing for votes alone is pretty large…
Damn it - I made a mistake
Ok, re-reading the documentation again, I made a major error interpreting these results.
mean_exec_time double precision: Mean time spent executing the statement, in millisecondsAll my statements about INSERT on Likes taking 1/3 of a second are wrong, it’s less than 1 millisecond. Although it sure doesn’t feel that fast when you are interactively using Lemmy 0.18 and pressing the Like button, it seems rather sluggish. I’ve almost never seen fractions of a milliseconds, but here it is.