Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect (6874 Views)
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Established Member
Mohd Amirul Ridzal Mohd
Posts: 2
Registered: ‎03-17-2011
Message 1 of 11 (6,874 Views)

Cannot connect to Media Agent port 20026 (IPC Cannot Connect

Hi

I running DP6.0 on a HP-UX machine. run a daily backup with error below. I've done nothing on the log files and the error just suddenly came out and kept for a week already.

[Critical] From: BDA-NET@madgn02d.newcos.com "madgn02d.newcos.com [/ORACLE/archd/TST16]" Time: 4/12/2011 10:45:57 AM
Cannot connect to Media Agent on system ndcbk01b, port 20026 (IPC Cannot Connect
System error: [238] Connection timed out
) => aborting.

anybody have same problem before? dear gurus...please advice.. :)
Honored Contributor
Eblyn Solis
Posts: 1,324
Registered: ‎10-19-2007
Message 2 of 11 (6,874 Views)

Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect

Hi,
concerning â Ipc subsystem reports: IPC Read Errorâ and backups timing out. These types of errors tell us there was a network problem during the backup that prevented Data Protector from maintaining an open connection between the cell server, disk and media agents, and therefore the backup was aborted. Data Protector is reporting the problem but usually Data Protector itself is functioning correctly.

Poor network performance causes overloaded connections between Disk Agent systems and the Media Agent system, resulting in connection drops and finally the session timeouts and the backup is aborted.

Try this:
Add the following uncommented statements to the system's omnirc file:(add in both servers)

OB2IPCKEEPALIVE=1
OB2SHMIPC=0

Details:

OB2IPCKEEPALIVE=1 to all clients DA + MA. The keepalive parameter just turns on the system mechanism for keeping connection alive for all the connection we make.

OB2SHMIPC=0 should be set on the cell manager and all client systems (at least to the systems reporting Critical and Abort errors). Improves handling of shared memory and may improve Network throughput.


Regards

Trusted Contributor
Henry A.C. Jansen
Posts: 253
Registered: ‎06-25-2009
Message 3 of 11 (6,874 Views)

Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect

Somebody installed a supportpack and activated a firewall ??
Frequent Advisor
Pankaj K gupta
Posts: 56
Registered: ‎01-19-2011
Message 4 of 11 (6,874 Views)

Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect

Is there any Firewall between cell manager and backup node , if yes open the ports from 20026-20036. while dp communicate with media agent it select random ports between 1025-65535
Honored Contributor
Jan Soska
Posts: 1,236
Registered: ‎01-22-2008
Message 5 of 11 (6,874 Views)

Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect

Hello,
we have very similar problem (after upgrading 6.11 to 6.2, maybe it is irelevant) in our X86 enviroment. We are quite sure there was no firewall change on linux host where media agent runs.
HP support say reconfigure portrange and update firewall, but it seems to me DP can use media agent on standard inet port 5555.
Am I right?

Jan
Trusted Contributor
Henry A.C. Jansen
Posts: 253
Registered: ‎06-25-2009
Message 6 of 11 (6,874 Views)

Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect

Initialy DP communicates between DA and MA on port 5555 to establish a communication path. Controldata is exchanged on this port to the CM and back. However the actual dataflow is done on a lot of other dynamically assigned ports for that session in the highend range like 10000 and above..
Honored Contributor
Jan Soska
Posts: 1,236
Registered: ‎01-22-2008
Message 7 of 11 (6,874 Views)

Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect

Hello, is there any documentation for that? I checked instalation guide and there is no mentions about media agent firewalls/rules/setting

Jan
Trusted Contributor
Henry A.C. Jansen
Posts: 253
Registered: ‎06-25-2009
Message 8 of 11 (6,874 Views)

Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect

Check this thread: http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=878577 or http://forums13.itrc.hp.com/service/forums/questionanswer.do?threadId=658846&admit=109447627+1306825... It's is also described in a manual but I'am not able do dig it out right now.. If you need it I'll try later..
Occasional Visitor
Karamba
Posts: 1
Registered: ‎12-31-2013
Message 9 of 11 (2,454 Views)

Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect

[ Edited ]

Hi,

 

You can specify ports on the media agent, for example :

/opt/omni/.omnirc or <DP_Home>\omnirc (on Windows)

 

OB2PORTRANGESPEC=CRS:4800-4804;xSM:4900-4964;xMA-NET:18000-18015

and add this ports to the your firewall.

 

Regards,

HP Expert
Bob_Clark
Posts: 1,433
Registered: ‎08-14-2013
Message 10 of 11 (2,446 Views)

Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect

An error like this

 

Cannot connect to Media Agent on system ndcbk01b, port 20026 (IPC Cannot Connect

 

is almost always an indication that there is a firewall involved.  As was previously mentioned, port 5555 is used for the systems involved (Cell Manager, Disk Agent, Media Agent) to establish communication, but, after that Data Protector used Dynamic Port Allocation to use any available port for data transfer, in your case 20026 was chosen at random

 

You need to get together with your Firewall Administrator, and have him establish a rule to allow a certain range of ports, maybe 20 or so, to be used for Data Transfer. Once this rule is established, you need to add a line to the 'omnirc' file to reflect this range of ports

 

OB2PORTRANGE=[port number]-[port number]

 

So, for example, if the Firewall administrator has established a rule for ports 20020 thru 20040 to be used for backup, the line would read

 

OB2PORTRANGE=20020-20040

 

This must be done BOTH on the disk agent being backed up, and the media agent.  Rember, when edit teh 'omnirc' file on Windows, you must stop and restart the Data Protector iNET service

 

You can read more about this by clicking, in the GUI, on Help -> Topics, and searching for OB2PORTRANGE.  Also, if you still have your DP 5.5 Admin Guide (I'll never throw mine away), you can review Chapter 13, which explains it in much more detail.  This Guide can also be downloaded from

 

http://support.openview.hp.com/selfsolve/document/KM532906?searchIdentifier=-7ba5f919%3a14336a1f354%...

 

Someone else suggested using OB2PORTRANGESPEC, while this will work just as well, I find it to be overly complicated, and hardly ever use it

Occasional Visitor
Maaran
Posts: 1
Registered: ‎01-06-2014
Message 11 of 11 (201 Views)

Re: Cannot connect to Media Agent port 20026 (IPC Cannot Connect

Sometime it could be DNS issue with Master server. Please kindly check it. Thanks

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