XCOM for Linux to z/OS daily transfer job has slowed significantly
Article ID: 416724
Updated On:
Products
Issue/Introduction
Have been experiencing significant slowness with daily XCOM job transferring data from Linux to z/OS which starts
Historically, this job started around 01:30 AM and completed before 02:00 AM.
Recently gradual slowness had been noticed and the job now routinely finishes between 03:00 AM and 04:00 AM i.e. the XCOM process can take over 2 hours to complete.
Environment
XCOM™ Data Transport for UNIX/Linux 12.0
XCOM™ Data Transport® for z/OS 12.0
Resolution
There have been no XCOM maintenance updates or configuration changes since the slowness started. Therefore it is more likely this gradual performance degradation has nothing to do with XCOM and is most likely network related. If for example XCOM trace had been enabled somewhere it would be expected the impact to have been large from day 1 and would not be gradually degrading as reported.
Customer ran same file transfer test with same XCOM configuration at a different time of day.
- At 11:33 AM it took 24 minutes @ 16123266 bytes/second.
- The same regular job earlier that morning had taken 1hr 56mins @ 3324977 bytes/second
As there is no change to any XCOM configuration or parameters between the 2 runs again that strongly indicates a network related issue.
Also tested the opposite z/OS outgoing transfer, the job log for 10 "TYPE=EXECUTE" transfers each with different file sizes (record numbers) and varying transfer times. The job start/end times were 02.21.29/04.11.04 so a duration of around 1hr 50 mins.
The time of the job execution also matches up with the "early hours" slowness symptoms when the file transfer is initiated from the Linux server side.
In summary all the results strongly indicate there is some network performance issue during the very early hours of the morning. Perhaps some maintenance activity is taking place that is having an impact.
Therefore asking the network team to perform a network trace to check the performance at that time of day is the next step.
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