We have verified that logtash is the main culprit in dropping the logs.
we are generating logs from LOIC with 800 logs per second and sending it to rsyslog. rsyslog agent is receiving all the logs even it is showing some count on the upper side , i mean if i sent 3000 logs from LOIC it always shows me that it receives 3020 logs , don't know about these 20.(According to my imstat file) Now again rsyslog passes these logs to logstash which at the moment has 15 filters. The metric to count the logs recived at logstash is http://logstash.net/docs/1.4.1/filters/metrics#flush_interval , but it always showed me the less number as i received in rsyslog. At certain level for example ,,3000 logs/5 sec, count of rsyslog and logstash is same but after 3500 , 4000 there is a difference of 30 -40 logs between rsyslog and logstash , our connection between rsyslog to logstash is TCP , so there should be no reason for this difference , either logstash is unable to parse all the msgs or rsyslog is sending less msgs to logstash. Any clue? On Sunday, May 18, 2014, David Lang <[email protected]> wrote: > If you are sending the right contents in the packet, LOIC should be just fine. > > Now, you haven't said what version of rsyslog you are using, your configuration, or even talked about what speed network you are on (let alone system specs), so figuring out what's wrong is not possible yet :-) > > That said, we've had people getting around 400,000 packets/sec through rsyslog, so you are probably not hitting any fundamental limit at 10,000 packets/sec. But there are a lot of things to look at to figure this out. > > start by configuring impstats (set it to dump stats every 10 sec for now at these traffic levels) so that we can see the what's happening inside rsyslog (to see if the problem is getting the logs in, or out of rsyslog) > > version info (rsyslog, distro, kernel) > > when you say you put things on a switch, is this a 100Mb switch, Gb switch, managed (so you can get stats from the switch)???? > > what's your rsyslog config? > > what do you use for name resolution (/etc/hosts, local DNS, nearby DNS, ISP DNS, LDAP, ????) > > UDP isn't necessarily faster than TCP, but it's a whole lot easier to setup a UDP test, so let's stick with that for now. There's nothing in the syslog protocol to add reliability to UDP > > David Lang > > > On Sun, 18 May 2014, masoom alam wrote: > >> Dear All, >> >> I hope every one is doing fine. We were doing stress testing of Rsyslog and >> found few problems (in our setup and not in Rsyslog :)) that I want to >> discuss at this forum. >> >> >> 1. We were using LOIC (LOIC is DDOS attack tool - your anti virus will >> delete it :) - disclaimer: handle it with care) for generation of UDP >> packets. We created a customized log message. The speed of Packets sent by >> LOIC is very very high, that is some thing 20,000 packets in 2 sec. for >> example. Every thing is fine if we use point to point connection between >> Rsyslog machine and MangoDB machine. Point to point means connection via >> cross cable and not through a switch. We calculated the no. of packets sent >> by LOIC and no. of packets received by Rsyslog and then written by MongoDB >> after parsing by Logtash is fairly equal. >> 2. However, if we connect both MongoDB and Rsyslog through a switch LAN, >> there is a packet drop at the Rsyslog end, some what between 300-500 >> packets depending on the speed of LOIC - thus 300-500 lesser logs are >> written to MongoDB. >> >> >> What we concluded and I want your expert opinion on this: >> >> >> 1. It seems LOIC is the not the right choice for traffic generation for >> Rsyslog - that is stress testing of Rsyslog. It sends packets via UDP 514, >> but essentially it does not follow Syslog Protocol. Now, we are trying to >> understand: Is there some sort of reliability achieved in Syslog protocol >> even if packets are sent on UDP 514? BTW, i am well aware that UDP is for >> faster communication but at the expense of reliability. Why we are saying >> that there is a problem at the LOIC - that is traffic generation end - >> because when we selected to send traffic via TCP on LOIC, due to speed it >> combines log packets and Rsyslog reports an error in its log. The net >> effect of this operation is that Rsyslog combines arbitrary no. of logs >> together and then give to Logtash, which does not understand and leave it >> un parsed. >> 2. What options do we have, either we use a python library to generate >> traffic, write it to /var/log/messages and ask the Rsyslog to send that >> traffic to another Rsyslog?. Does using this way guarantees that there will >> be no drop of Log messages even in UDP? >> 3. But what I am interested in understanding what is the reliability >> mechanism provided by Rsyslog in general in the case of UDP. After all each >> n every log is a very important piece of information and can destroy the >> reputation of an organization. >> 4. Even if the some reliability can be achieved at the Rsyslog end, how >> can we avoid - up to maximum extent - the possibility of log drop between >> Rsyslog to Logtash. Logtash is a very small program than Rsyslog. Rsyslog >> in our setup is used only for Buffering - thus, what parameters in the >> .conf file of Rsyslog should be changed to achieve this reliability. Please >> note that, our Rsyslog and Logtash are setup at the same system - so no >> network latency at this end. >> 5. In all this setup, the performance of LogAnalyzer was very pathetic >> in filtering and running other queries. So we choose to write a simple PHP >> web page for displaying logs and it is running much much faster than >> LogAnalyzer. >> 6. Are we on the right path for checking reliability and stress testing? >> _______________________________________________ >> rsyslog mailing list >> http://lists.adiscon.net/mailman/listinfo/rsyslog >> http://www.rsyslog.com/professional-services/ >> What's up with rsyslog? Follow https://twitter.com/rgerhards >> NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad of sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you DON'T LIKE THAT. >> > _______________________________________________ > rsyslog mailing list > http://lists.adiscon.net/mailman/listinfo/rsyslog > http://www.rsyslog.com/professional-services/ > What's up with rsyslog? Follow https://twitter.com/rgerhards > NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad of sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you DON'T LIKE THAT. > -- Sent from noir _______________________________________________ rsyslog mailing list http://lists.adiscon.net/mailman/listinfo/rsyslog http://www.rsyslog.com/professional-services/ What's up with rsyslog? Follow https://twitter.com/rgerhards NOTE WELL: This is a PUBLIC mailing list, posts are ARCHIVED by a myriad of sites beyond our control. PLEASE UNSUBSCRIBE and DO NOT POST if you DON'T LIKE THAT.
