"Communication link failure" state:"08S01" on a connection pool

Any changes should just have to be done in JavaScript: Connections have a .connected property that calls SQLGetConnectAttr with the SQL_ATTR_CONNECTION_DEAD option. Returns true if SQL_ATTR_CONNECTION_DEAD returns false (since it makes much more sense for .connected to return true if its… connected). I imagine the code would just check:

if(!connection.connected) {
// close connection
// open a new connection and add it to pool
}

Maybe the issue is here: https://github.com/markdirish/node-odbc/blob/69f49bd4703e569ef01693f4d9241bcdeffa5b00/lib/Pool.js#L253

I think an assumption is being made that the connection that’s being popped is a good connection, and perhaps connection.connected should be checked on the popped connection. This will make sure the connection is good and if its not, to create a new connection.

Unless the developer using the node-odbc pool is expected to try catch when they run pool.query and catch the connection error message

State 08S01 Code 10054 [IBM][System i Access ODBC Driver]Communication link failure. comm rc=10054 - CWBC01047 - The IBM i server application disconnected the connection.

Then reinstantiate the pool. Which seems odd to me since I feel the pool should be gracefully handling dead connections without the developer needing to do anything.

 pool = await odbc.pool({
    connectionString,
    initialSize: 5,
    maxSize: 10,
  });

Going back to the php_odbc.c source comparison. node-odbc doesn’t have a

goto try_and_get_another_connection;

It just has a function to check for a dead connection. It would be nice if node-odbc realized it had a dead connection and replaced it with a new connection.