[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[LDM #NVP-211237]: LDM help: "NOTE: Denying connection from [*********] because too many clients."

This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.

  • Subject: [LDM #NVP-211237]: LDM help: "NOTE: Denying connection from [*********] because too many clients."
  • Date: Sat, 06 May 2017 10:46:16 -0600
Derek,

> We have been seeing many of the:
> 
> "NOTE: Denying connection from...  ...because too many clients"
> 
> messages in our ldmd.log files.
> 
> Currently we have our $max_clients set to *512.*

That's more than we run. Of course we split the connections amongst 6
backend servers.

> When I run an ldmadmin printmetrics
> 
> ldm@vm-lnx-mrms-ldmouta ~/logs]$ ldmadmin printmetrics
> 20170505.145304 22.83 19.32 17.76 *278* 0 1606 14391 11999017944 3 4 89 4
> 15926720e3 407088e3 535676e3 7697280e3 4054
> or a netstat:
> 
> netstat -a | awk 'NR<=2 || /ldm/'|wc -l
> 289
> 
> My connection count always appears to be *under 300.*
> 
> Couple questions:
> 1.  Is there a reason to think that I am occasionally bumping into the 512
> limit and I should increase the max_clients value, or is there some place
> else we should be investigating?

Your LDM is running into the 512 limit. Hopefully, there's not a bug in the LDM
6.8 code that cause it to think there are more upstream LDMs than actually 
exist.

> 2.  Is there a maximum number that the $max_clients value can or should be
> set to?  (is there a performance hit if we allow for too many connections?)

At some point, either performance will degrade to an unacceptable level or the
LDM will hit an operating system limit (e.g., the number of open file
descriptors). Until then, go for it.

> FYI   We are running an antiquated version of LDM  6.8.1

If you upgrade your LDM, then you can use the new utility uldbutil(1) to list 
all
the upstream LDM processes on your system that are sending to a remote 
downstream
LDM.

Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: NVP-211237
Department: Support LDM
Priority: Normal
Status: Closed
===================
NOTE: All email exchanges with Unidata User Support are recorded in the Unidata 
inquiry tracking system and then made publicly available through the web.  If 
you do not want to have your interactions made available in this way, you must 
let us know in each email you send to us.