We recently upgraded to Spark 2.8.3 and seems fine, for a short time at least. File and image transfers only work at our local network, but fail if the second subnet is involved. The openfire server (4.1.3) run on a system with to subnets till the upgrade. We did some experiments with different version of Spark including the NightlyBuilds. Till Spark version 2.7.7. the file transfer work but is not very fast. I assume the “proxy server file transfer” (port 7777) failed and Spark fall back to “In-Band File Transfer” (based on Ignite Realtime: IM File Transfer Made Easy ), so far so good. The newer versions of Spark seem to fail on “In-Band File Transfer” too. Currently we downgraded our Spark clients to version 2.7.7. and it work so far. Is there a other solution to work with newer Spark version?
This is a side effect of updating to newest Smack. No solution so far. Filed as [SPARK-1869] Degraded file transfer feature when sending files between different networks - IgniteRealtime JIRA