[ldm-users] How to control LDM batching RPC requests every 30 seconds?

• To: "ldm-users@xxxxxxxxxxxxxxxx" <ldm-users@xxxxxxxxxxxxxxxx>
• Subject: [ldm-users] How to control LDM batching RPC requests every 30 seconds?
• From: "Herzmann, Daryl E [AGRON]" <akrherz@xxxxxxxxxxx>
• Date: Mon, 3 Jul 2023 15:05:22 +0000
• Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=iastate.edu; dmarc=pass action=none header.from=iastate.edu; dkim=pass header.d=iastate.edu; arc=none
• Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=Di1h3yeEItc5ZpXUwwcZ88rccHRI7NQix/o1SXf256w=; b=bcdW2aQsgrfsGh07PgCYYaFtH9rSqmHSAEOftUAdwupaUjGynpe07J/zFZs1NSraOuAsDgaz18C5Fvr1i+ASWZV8YjfUn6LB/NZRaS2kfKfVkV/H+cKOtsEFnZ/lnsfPaFvZaWMEtTBFejAHyK9an5lpPVYt114BE8+Kvv0MRZqqpGJDUW184js3QN69LTJkqOWmME3LoGFq96S9u5FG4bl9dmX8TzWfJAZSZEl/3PF810AqiKw9fU0idVnqEGNW/W/p+sj9tveT9AyndSsD/HEZy1I7WnsAoThg+XMk7RvKXxgAdMoZSJwRUjhxx102OB/LFvIY36H3XIFV2UiQ6g==
• Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=YJEibh0f2aURPVq5aD6Jkb7HQIEPmznhPOXrQqORmSZK8kyMNXX1Rrdqx6d3+PeB91ladCnIR+aLHugrXExDRhrkHFX5b+UQolz35hPmk2aFF9HePBS0eo9f/4Yw2+i3Ea5f+Pq7mI6sOJwaMZ66fmQHqou8CGF3a1fcSUdEomrFxBAxF+bUTViwvr7qSpaIOq1WSRHF2YK3YqfvSn6wbE0yPLkb34YO4RMBFpOveEbNRKbm0U87caAOU8Ije3sbxsa+vf1+BFq2lEYSgnvHk+1vBN6NNoamiMmb9bAmoXTMphTb+iZajr8StuvllTpXep7FCmTQxxdZ6pfpjJhAiw==
• Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=iastate.edu;
• Msip_labels:

Howdy LDM Users/Unidata,

I'm attempting to get straight in my head some relay latency between a LDM 
server and client.  Both are running the current release, 6.14.5.  My simple 
test is as follows, on the LDM upstream

    pqinsert something every two seconds

on the LDM downstream, monitor receipt of these inserted products via `ldmadmin 
watch` and also putting the LDM client connection into debug mode to see what 
the RPC is doing.  What I observe appears to LDM batching the RPC calls every 
30 seconds instead of a more timely relay of inserted products to downstreams. 

My typical naive and likely wrong understanding of LDM's code is that this is 
controlled by:

src/registry/globals.c
/*
 * Time to sleep in pq_suspend() and before retrying connects.
 */
unsigned int            interval = 30;

So my questions:

1) Is this latency a function of my usage of `pqinsert` on the server side 
instead of some proper LDM forked child process?

2) Are there side effects / significant performance concerns of setting the 
`interval` value above to some lower threshold?  I am thinking about setting it 
to 1 or 5 seconds.  Do I need to be careful to change this on all my LDM 
servers and clients in my local topology?

3) Is there some other setting that controls this batching of RPC from the 
server to the client?

thanks and Happy 4th!
daryl

• Follow-Ups:
  • [ldm-users] 20230703: Re: How to control LDM batching RPC requests every 30 seconds?
    • From: Tom Yoksas