Correct way to close connection

[iamDonkey]

In the pool based usage What is the correct way to close the connection after query is executed? conn.end() or conn.release() ???

[rusher]

The correct way is to use conn.release() (see documentation https://github.com/mariadb-corporation/mariadb-connector-nodejs/blob/master/documentation/promise-api.md#poolgetconnection--promise)

(To avoid any issue, conn.end when connection comes from pool just is just a reference to conn.release)

[iamDonkey]

thanks.

[iamDonkey]

Despite releasing connection back to pool after idle for sometime i am getting this error. i think all connection in the pool are dead. how to configure to reconnect if connection closed by server for inactivity?

SqlError: (conn=-1, no: 45028, SQLState: HY000) retrieve connection from pool timeout after 2001ms 
    at Object.module.exports.createError (/root/node_modules/mariadb/lib/misc/errors.js:56:10)
    at Pool._requestTimeoutHandler (/root/node_modules/mariadb/lib/pool.js:332:18)
    at listOnTimeout (node:internal/timers:559:17)
    at processTimers (node:internal/timers:502:7) {
  text: 'retrieve connection from pool timeout after 2001ms',
  sql: null,
  fatal: false, 
  errno: 45028,
  sqlState: 'HY000',
  code: 'ER_GET_CONNECTION_TIMEOUT'
}
Total connections:  0
Active connections:  0
Idle connections:  0

[iamDonkey]

do i have to use minimumIdle option in the pool?

[rusher]

minimumIdle is by default set to connectionLimit, so that's not the problem here.

normally, connection in pool can be be wrong state if not used for some time (server close socket after reaching @@wait_timeout value => default to 8 hours), but that's not an issue, because pool will validate those connection, discard them, and recreate new one. Creating new connection usually takes around 50ms, it slow query a little bit, but after beeing unused for 8h, that not a big deal. This can even be avoided setting pool option idleTimeout in order to validate connection in pool regulary.

Your message is very strange, with "Total connections: 0". Connection creation takes some time, but a lot less than 2000ms. Do you use some serverless implementation that makes some time to wake up ?

[rusher]

closing since no answer since 9 month