Thanks for the answer, I'm happily surprised to see that we're still far from xymon's limit.
I made more checks today, and realized that some tools that I thought were sending their statuses over a few seconds actually send batches of ~200 statuses in 200ms. These burst are definitely far higher than 200msg/s... I had no idea that our traffic was so irregular. I guess that, as you pointed out, the next step is to setup xymonproxy and have the few tools that generate so much traffic use them. As the only thing they know about xymon is the status command, that should be quite easy to set up.
Regarding the history files, it is not an issue as far as performance is concerned, but it definitely is a pain to manage. Moving to database solution has been in our todo list for some time now.
Regards,
Francois Maillard
De : Clark, Sean [mailto:sean.clark at twcable.com] Envoyé : mercredi 17 décembre 2014 19:46 À : MAILLARD Francois Ext DTSI/DSI; xymon at xymon.com Objet : Re: [Xymon] xymon on a large architecture
So I have a setup where, in total, I monitor about 300,000 hosts.
It's regionalized though, with the largest site having roughly 34,000 hosts
The xymon daemon runs on a VM, with 16 GB of Ram, and 4x2.5 Ghz xeon processors. The virtual NIC is a 1000Mb
It currently handles 481 msgs/sec (the hosts.cfg is 1.2 Mb)
Here are some ideas:
(1) Obviously split pollers out into separate machines (2) Change the history daemon (Henrick as some sample daemons in the source code) - I changed it to write stachg and clichg and such are written out to mysql instead of files, and the textblog is compressed. This helped with managing history (3) Use JC Cleaver's patches http://terabithia.org/rpms/xymon/ -- he has several memory leak fixes, tuning optimizations. I would just say that if you use clientupdate, you will have to patch his things a little bit (4) An interesting thing you can do, if you have the means via a load balancer is --> (a) I have 10 pollers for this instance. All of them run xymonproxy on localhost (stuff they poll reports to localhost and gets forwarded up) (b) Using a load balancer for they xymon IP address, it inspects the first 12 characters of a xymon message - if it's something that can be combo'd in proxy it passes to a poller in the pool, otherwise, it sends it to the real xymon IP (5) JC has some nanomsg options for channels, and myself, I use AMQP for channels to communicate data outbound. Both of these help if you use xymondata outside of the stock app
For your setup, rather than running more xymond's on different ports, setup xymonproxy's on different machines, and point your clients to them. Then you won't have to migrate your history files or anything else. But I would look at changing your history setup, as several million files gets very unwieldy to manage, but millions of rows in databases are much easer to do.
From: "fmaillard.ext at orange.com<mailto:fmaillard.ext at orange.com>" <fmaillard.ext at orange.com<mailto:fmaillard.ext at orange.com>> Date: Wednesday, December 17, 2014 at 11:04 AM To: "xymon at xymon.com<mailto:xymon at xymon.com>" <xymon at xymon.com<mailto:xymon at xymon.com>> Subject: [Xymon] xymon on a large architecture
Hello,
We're running a quite large xymon setup, and have been dealing with performance issue for quite a while. Here are some stats to give an idea about the setup:
- We have 2 xymon servers per datacenter, on 3 datacenter (all messages are sent to both servers for a given site)
- Each xymon server receives on average between 200msg/s and 250msg/s. We're getting peaks at 400msg/sec.
- Each site hosts about 3000 hosts / 30 000 services
We've been suspecting for a long time that we might be losing messages... and I think I finally tracked it down to xymond not fetching the messages quickly enough so that the kernel's buffer fill up and messages get discarded (by the kernel). On one of our servers, even though I have already increased net.ipv4.tcp_rmem and net.ipv4.tcp_wmem I got the following output from "netstat -s": 148909 packets pruned from receive queue because of socket buffer overrun 4453143 packets collapsed in receive queue due to low socket buffer
And here I come to the question I'm having: 1/ Is 250msg/s too much for a single xymond instance? Is anyone running instances with a lot more traffic than that? 2/ I'm starting to look into running several instances of xymond on the same machine, by binding them to different ports. Another option is to set up new machines, but that would mean migrating history files (several million files), sorting out the firewalling issues (our xymon interfaces are deeply connected to our information system) so I'd rather like avoiding this option. Are there any guidelines on how to do this? 3/ Are there any settings and best practice that could improve performance? For instance, should we move to a massive use of combo statuses in order to lessen the number of messages received?
Best regards,
Francois Maillard
Pilote des plateformes Supervision, DNS & FTP - Sysadmin Infrastructure Altran Méditerranée pour Orange/OF/DTSI/DSI/DFY/HBX Sophia Antipolis tél. 04 97 12 87 53 fmaillard.ext at orange.com<mailto:fmaillard.ext at orange.com>
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