New on LowEndTalk? Please Register and read our Community Rules.
All new Registrations are manually reviewed and approved, so a short delay after registration may occur before your account becomes active.
All new Registrations are manually reviewed and approved, so a short delay after registration may occur before your account becomes active.
Rsyslog
Just a heads up to those who use rsyslog on VPS's, reducing the stack size leads to huge improvements in memory usage!
The first recorded data is eronous.
Second, the normal settings
Third a 1mb stack size
Fourth 256k stack size.
I tested the stack size of 256k (as apposed to 8M) on a lab box for a good 48hours before deciding it was time to push it out, so it should be stable for most workloads. Don't sue me
No syslog server (even one as amazing as rsyslog) should need more than 100mb of ram.
Comments
I'm not going to try that on my production boxes here. Just looked at the numbers and we are hitting about 50.000 log messages/hour here... But for my vps I can try
Im currently running it on multiple boxes pushing about the same via relp (about 12 threads in some distant locations) without any issues so far.
The memory reduction is amazing
These servers arent exactly small but 100mb of ram freed is easily allocated to more important stuff.
Good luck.
Is this really causing a problem? That's "just" address space, not real memory that is being used. If it is a problem, I could probably add a config setting in rsyslog to specify a stack size. The size by default is large, as some folks push crazy large messages through the system. I would appreciate replies to [email protected] (especially late ones), as I do not routinely monitor this forum here. Thanks! Rainer
I got to admit it was a problem for me, I don't have swap being that I am on a VPS. By optimizing the stack size of rsyslog I was able to add another 50mb to redis without any stability issues or increase in cost. And gain a little extra stability that comes from having a little free ram (for bursting in other applications).
All of my messages are sub 250 characters (most sub 50) so I may be an outlier, although I expect not. I just transmit error logs from a few applications, traffic logs and a "combined apache" formatted logfile.
Good work with rsyslog, relp is really useful where UDP can be unreliable and TCP prone to issues.
Thanks for the clarification. Makes sense to me. I'll see if I can add such a parameter in new versions.