Memory loitering in driver for reused connections and protocol path that doesn't reset affectedRows and insertIDs accumulators

[aforrest-google]

Issue description

After the introduction of #1263 which adds support for multiple rows affected and insert IDs being returned for multi-statement requests, there are some conditions that lead to a memory loitering issue (both must be true):

1. If the connection is reused
2. If the protocol path involved results in an OK Packet (e.g. a resultSetHeaderPacket)

Notably, the Query path in the driver implementation is affected by this second condition. Any extremely long running process that continually reuses a connection and uses the Query path (as opposed to the Exec path) will experience this issue.

Example code

  for {
    if err := conn.Ping(); err != nil {
      return err
    }
    time.Sleep(time.Second)
  }

Error log

Not applicable.

Configuration

Driver version (or git SHA): 1.6

Go version: 1.17

Server version: MySQL 5.7

Server OS: N/A

[aforrest-google]

I have a PR for this. Will mail shortly.

[aforrest-google]

Going to collaborate with author of unmerged PR # 1263 to submit the PR that would address this issue. Closing.

[mherr-google]

This is fixed in 2e231fa.