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[LDM #JCM-759529]: Problem getting data from upstream source



James,

The TCP layer on Horus is receiving a reset (RST) packet when it initiates a 
TCP connection to Aeolus. This behavior is consistent with 1) a firewall rule 
that disallows TCP connections to port 388 from Horus to Aeolus; and 2) the 
absence of an entry in the LDM configuration-file on Aeolus that would allow a 
connection from Horus.

You should check the firewall rules on Aeolus and also Aeolus' LDM 
configuration-file.

To diagnose the problem more conveniently, your system administrator can bypass 
the LDM on Horus by executing the command "telnet Aeolus 388" on it.

Please keep us informed.

> Our Department has two servers that ingest data using a ldm.
> Indra.atmos.ucla.edu is the primary server while horus.atmos.ucla.edu
> acts as a secondary server(i.e. back-up). Indra is currently working
> well getting data(primary source idd.unidata.ucar.edu; failovers
> iddb.unidata.ucar.edu and aeolus.ucsd.edu...also can source
> idd.aos.wisc.edu for Conduit data if needed).
> 
> The problem concerns Horus. Recently this summer, Horus was moved to a
> new room. Because it now exists in a different building from before, its
> IP address was changed(from 128.97.77.43 to 169.232.145.76)...wiring in
> that building required use of a different subnet).  Horus normally feeds
> from Indra, but it can failover to one of the other sites that Indra
> uses. The problem is that now requests from Horus are only accepted by
> Indra. The ldmd.log files show repeated lines similar to the following:
> 
> 20160826T203753.097695Z aeolus.ucsd.edu[16283] NOTE
> requester6.c:588:req6_new() LDM-6 desired product-class:
> 20160826193753.097643 TS_ENDT {{NGRID|NIMAGE, ".*"},{NONE,
> "SIG=7196a6d7d035c6b66e2e31737a761167"}}
> 20160826T203753.142376Z aeolus.ucsd.edu[16283] NOTE
> error.c:236:err_log() Upstream LDM didn't reply to FEEDME request; RPC:
> Unable to receive; errno = Connection reset by peer
> 
> It doesn't matter which outside source that the ldm calls upon for
> various data types. The upstream site apparently doesn't reply to the
> requests sent by Horus. Both servers are running ldm-6.13.2, and Horus
> didn't have a problem until its move(and change of IP). There was an ACL
> restriction on the subnet that Horus now is on, but port 388 was cleared
> for the server.
> 
> I'm asking for suggestions on what our systems administrator can check for.

Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: JCM-759529
Department: Support LDM
Priority: Normal
Status: Closed
===================
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