We have encountered a case where PgCat pools were stuck following a database incident. Our best understanding at this point is that the PgCat -> Postgres connections died silently and because Tokio defaults to disabling keepalives, connections in the pool were marked as busy forever. Only when we deployed PgCat did we see recovery.
This PR introduces tcp_keepalives to PgCat. This sets the defaults to be
keepalives_idle: 5 # seconds
keepalives_interval: 5 # seconds
keepalives_count: 5 # a count
These settings can detect the death of an idle connection within 30 seconds of its death. Please note that the connection can remain idle forever (from an application perspective) as long as the keepalive packets are flowing so disconnection will only occur if the other end is not acknowledging keepalive packets (keepalive packet acks are handled by the OS, the application does not need to do anything). I plan to add tcp_user_timeout in a follow-up PR.
* Initial commit for graceful shutdown
* fmt
* Add .vscode to gitignore
* Updates shutdown logic to use channels
* fmt
* fmt
* Adds shutdown timeout
* Fmt and updates tomls
* Updates readme
* fmt and updates log levels
* Update python tests to test shutdown
* merge changes
* Rename listener rx and update bash to be in line with master
* Update python test bash script ordering
* Adds error response message before shutdown
* Add details on shutdown event loop
* Fixes response length for error
* Adds handler for sigterm
* Uses ready for query function and fixes number of bytes
* fmt
* Refactor query routing into its own module
* commments; tests; dead code
* error message
* safer startup
* hm
* dont have to be public
* wow
* fix ci
* ok
* nl
* no more silent errors
* constants
* server.rs docs
* client.rs comments
* dead code; comments
* comment
* query cancellation comments
* remove unnecessary cast
* move db setup up one step
* query cancellation test
* new line; good night
