[] Why we need to support use MultiNodePipelineBase in multi thread?

[xrayw]

I found these codes.

https://github.com/redis/jedis/blame/1d1b268f9be5b093f6684bc814d2fdab376a1ee3/src/main/java/redis/clients/jedis/MultiNodePipelineBase.java#L54-L56

Connection newOne = getConnection(nodeKey);
connections.putIfAbsent(nodeKey, newOne);
connection = connections.get(nodeKey);
if (connection != newOne) {
  log.debug("Duplicate connection to {}, closing it.", nodeKey);
  IOUtils.closeQuietly(newOne);
}

and the pr #3330.

This makes me confused.
The connections: LinkedHashMap, It's not a Concurrent Data Structures, Unexpected results may occur when used in multiple threads. So why we need add the code to support it under multi thread?

[ggivo]

It is a valid point.
Agree that the current code will not guarantee that there is no connection leak. Not aware if there is a use case to move in direction of making it thread-safe. Probably stillerrr can provide pointers on what the driver is for this change?
Since MultiNodePipelineBase as of now is not thread-safe, to reduce the confusion, we can document it properly with Javadoc.