-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Aurélien,
On 10/7/15 5:59 PM, Aurélien Terrestris wrote: > when this happens you can do a thread-dump (kill -3 pid on Linux > platforms) and you would see if there is a lock on JDBC objects, or > anything else synchronized (from the Collections like Hashtable). > Not easy for beginners to understand a dump, but worth learning. +1 This is the only way to find out what's going on. All other monitoring solutions will just tell you that *something* is wrong, but this will give you details. > Very often an application will slow down because Garbage > Collection, and the GC thread will be the only one working at that > time. Please use the verbose settings to have all your Tomcats log > GC activity. This is useful for both live and after time analysis. This is pretty unlikely for the reported observations, since Tomcat slows down and stops responding (presumably until restarted). That is more likely to be something like database connection pool being exhausted due to poor resource management rather than out-of-control GC activity. > You won't monitor mod_proxy, this has no sense. I disagree. The connection can go down for various reasons. But I suspect that's not the problem in this case. > If you suspect a network flood, do a 'netstat -an' to see how many > connections are used by your Apache (both ESTABLISHED and > TIME_WAIT). However, you might need to set timeout and flushpacket > on your proxypass directive when your application has such > requirements (see HTTPD doc for this settings). To know if you're > flooded, you can do a 'ps -eaf | grep [h]ttp' and you would see > many httpd process, it is similar to the netstat result more or > less. +1 > If you enjoy live monitoring, you need to have a look on > Christopher's presentation ( > http://events.linuxfoundation.org/sites/events/files/slides/Monitoring %20Apache%20Tomcat%20with%20JMX.pdf > > ) who posts many answers to this mailing list. Live monitoring is the only way to go, unless you want your customers to surprise you with performance problems on your own site. :) - -chris -----BEGIN PGP SIGNATURE----- Comment: GPGTools - http://gpgtools.org iQIcBAEBCAAGBQJWFqd5AAoJEBzwKT+lPKRYi9AQAIpHkOgXoz2Ntfdf8aH1mjTB gdKDu1B5fEgpTYRhV+mQ5rEegkszJ0jUEQdCVjwp2ZjldgsLPP6wXaBw6LdUG3UB l63K4tCkDwIiVI8rB0syAeQQ/4uUS7SmiJaLZAwLHl08mDZHs9e/LiKJ47rJjh3+ 4pkejtbHhobF2fcH61ZM7M5qxPKlzP49dDzXyppbvEG/kk7T9FkIl2TVOT349zkP c1jrtC19fKDhbz72c/03/Z1V/clZ+Q3BScYHddlRw0ZXuOEu8LQJRD0VPmEY4pM5 DTPH+z5spnYUO0hH0FHx/WGHgQ5iCrQHYG8pdkfhDEqSaDnqm4qIFxC4fChIFSuh c9eqor7axyOcacHvTCwPudXGuWBxK0LCnigikd83OM/EaKdRwR0ahMqXKEQkRdTn QW3vfsOQXXuy0vAFz6fphOkWXCr4SJWVOsAG3f1vlStMs2to4q66hpNQpLFJpcdN ectoRaCRvQMLdw9UhdG3z5wTCvPPj9RP8IA/Lxi48QisYOMZwABgh7mMh2+mE7pH tTHun4fE2HhdVPqORonHhTWldvu4xYqWav9FNBgg2ywyekAWVcrcFZRLgYhG+T37 0neZbSdwd/iLdsZ+sKhGY04CSwAsUZdTh87pZ+8NWH7tvi71JIt7nlI0JgRI5ipw Jdty982ew2WiaY0rhspW =Ra47 -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
