As EXASolution comes with its own operating system and users do rarely have access to that system, testing network connectivity can be quite hard. This makes debugging Import/Export/UDF that fail withtimeoutsorconnection refuseda lengthy task.
How to test HTTP connections using python UDF
The attached SQL file contains aSCALAR PYTHON SCRIPTthat does minimalistic network testing using the following steps:
Hostname lookupusing DNS (Domain Name Service)
TCP connectto the resulting address
HTTP 1.1 request
The script will output some information, including the cluster node it ran on and an elapsed time (in seconds).
1 - Testing an internal web server on a random node