This UDF coordinates connectivity checks accross the whole cluster.
This UDF gets the list of active readable nodes in the cluster, and
coordinates all connectivity checks in sequential order.
The algorithm is:
for sourceNode in activeReadableWorkerList:
c = connectToNode(sourceNode)
for targetNode in activeReadableWorkerList:
result = c.execute(
"SELECT citus_check_connection_to_node(targetNode.name,
targetNode.port")
emit sourceNode.name,
sourceNode.port,
targetNode.name,
targetNode.port,
result
- result -> true -> connection attempt from source to target succeeded
- result -> false -> connection attempt from source to target failed
- result -> NULL -> connection attempt from the current node to source node failed
I suggest you use the following query to get an overview on the connectivity:
SELECT bool_and(COALESCE(result, false))
FROM citus_check_cluster_node_health();
Whenever this query returns false, there is a connectivity issue, check in detail.
Hanefi Onaldi