Scheduler listening on random ( excessive ) ports?
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Scheduler listening on random ( excessive ) ports?

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Article ID: 186543

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Updated On:

Products

CA Workload Automation AE - Scheduler (AutoSys) Autosys Workload Automation

Issue/Introduction

We need to know what is the Scheduler listening on ports not mentioned in the config.$AUTOSERV file for.

TS1-autosys@hostname:/home/autosys
$ ps -ef|grep [e]vent_demon
autosys  27895     1  1 Mar09 ?        01:01:14 event_demon -A ST1
autosys  29713     1 19 Mar09 ?        18:02:34 event_demon -A TS1

TS1-autosys@hostname:/home/autosys
$ lsof -p 27895 | grep [L]IST
levent_dem 27895 autosys   33u  IPv6          346032961      0t0       TCP *:7515 (LISTEN)
event_dem 27895 autosys   39u  IPv6          346034471      0t0       TCP localhost:58995 (LISTEN)

 TS1-autosys@hostname:/home/autosys
$

 TS1-autosys@hostname:/home/autosys
$ lsof -p 29713 | grep [L]IST
event_dem 29713 autosys   33u     IPv6          346035899      0t0       TCP *:7514 (LISTEN)
event_dem 29713 autosys   39u     IPv6          346036176      0t0       TCP localhost:47023 (LISTEN)
event_dem 29713 autosys   40u     IPv6          346036179      0t0       TCP localhost:33779 (LISTEN)

Understand ports 7514 and 7515 are configured in the config.$AUTOSERV file (SchedAuxiliaryListeningPort):
 $ grep ^SchedAux /opt/CA/WorkloadAutomationAE/autouser.???/config.???
/opt/CA/WorkloadAutomationAE/autouser.ST1/config.ST1:SchedAuxiliaryListeningPort=7515
/opt/CA/WorkloadAutomationAE/autouser.TS1/config.TS1:SchedAuxiliaryListeningPort=7514

What are these ports 58995, 47023 and 33779 being used for?

$ netstat -ano | egrep '(58995|47023|33779)'
tcp        0      0 ::1:33779                   :::*                        LISTEN      off (0.00/0/0)
tcp        0      0 ::1:58995                   :::*                        LISTEN      off (0.00/0/0)
tcp        0      0 ::1:47023                   :::*                        LISTEN      off (0.00/0/0)

Environment

Release : 11.3.6

Component : CA Workload Automation AE (AutoSys)

Resolution

Those ports are ephemeral or dynamic ports that the scheduler allocates when it needs to communicate application servers or agents. Each dynamic port will be released when the communication ends. For example, if the scheduler needs to submit a job to an agent, it will allocate a dynamic port and connect to the listening port (by default it's 7520) of the agent.  The allocated dynamic port will be released when the job submission is done. The range of the ephemeral ports is set by the system on which the scheduler is running.

Here is a KBA for a different CA Product but it has information about ephemeral port ranges for various operating systems:

https://ca-broadcom.wolkenservicedesk.com/external/article?articleId=112430

You may also want to review the wikipedia article on Ephemeral ports:

https://en.wikipedia.org/wiki/Ephemeral_port