Connection pool - Blocking operations

[fwbrasil]

The connection pool performs block operations to acquire and test connections using the connection factory [1] [2] [3] [4]. This characteristic makes the pool really sensible to database issues, like high latency or connection errors.

The workaround for me was:

• Reduce the timeout for connection acquire and test by configuration (PR Connection factory timeouts #90)
• Use a partitioned connection pool (PR partitioned db pool #88)

I think that an ideal solution should be avoid having blocking operations inside connection pools.

[1]

postgresql-async/mysql-async/src/main/scala/com/github/mauricio/async/db/mysql/pool/MySQLConnectionFactory.scala

Line 53 in 2ab790d

Await.result(connection.connect, configuration.connectTimeout )

[2]

postgresql-async/mysql-async/src/main/scala/com/github/mauricio/async/db/mysql/pool/MySQLConnectionFactory.scala

Line 124 in 2ab790d

Await.result(item.sendQuery("SELECT 0"), configuration.testTimeout)

[3]

postgresql-async/postgresql-async/src/main/scala/com/github/mauricio/async/db/postgresql/pool/PostgreSQLConnectionFactory.scala

Line 53 in 2ab790d

Await.result(connection.connect, configuration.connectTimeout)

[4]

postgresql-async/postgresql-async/src/main/scala/com/github/mauricio/async/db/postgresql/pool/PostgreSQLConnectionFactory.scala

Line 90 in 2ab790d

Await.result( item.sendQuery("SELECT 0"), configuration.testTimeout )

[mauricio]

Okay, gonna get some work done on it this week and remove these blocking ops.

[fernandezpablo85]

any updates on these?

[mauricio]

@fernandezpablo85 any contributions are welcome :)

But I do plan to check the possibilities here.

[fwbrasil]

@mauricio I was wondering, do you have plans to work on this in the short tem? It's a major issue for high-load systems, so I've been avoiding suggesting quill-async to new users. I could give it a try if you don't have plans to work on it.

[kralikba]

@fwbrasil , @mauricio any updates on this?

[oshai]

We have fixed this issue in jasync fork of the lib. see this issue: jasync-sql/jasync-sql#41