-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Alec,
On 8/1/13 6:14 PM, Tomcat Random wrote: > I'm expecting 5000 simultaneous users, with a physical load > balancer to two physical app servers. So ~2500 per machine, each > running an instance of tomcat not fronted by httpd or any proxy > server. (i.e., using Tomcat to serve a few static assets along with > the webapp). Again, how many simultaneous /connections/ -- or requests -- do you expect to handle? The number of simultaneous users is really only relevant if you use sessions and then it comes down to memory (heap) and failover (replication) if you want it. What's much more important is the transaction rate. For instance, if you expect 5000 users (really ~2500 per instance) and they each make a request once per minute, than that's 2500 requests per minute or ~40 req/sec. If your average transaction takes longer than 1/40 sec (250ms), then you are in trouble because you will not be able to keep up with demand. If your users make 2 transactions per minute, then you need to have average transaction time down to 1/80 sec (125ms) or you will not be able to keep up. What happens if one host fails and the other one picks up *all* the traffic? That means you need to do the average transaction in 1/160 sec (62ms) or you will not be able to keep up. You might consider using a hot-spare or 3 instances. > "are you just interested in speculative performance tuning?" That's > correct - with just one user (myself) testing it everything is > wonderful. I've just got that uneasy feeling the servers will > explode when we flip over from our old host/codebase and get all > the traffic. JMeter is your friend. Put in the time to build workflow simulations. It will pay you back manifold. You can even use your JMeter load tests to do quick smoke-testing in production after a release just to make sure you didn't miss anything. - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJR/GnEAAoJEBzwKT+lPKRYx68QAJPE1VHVN4tX+cmssoaO3Qhr 4zjRtYYmpYna8L4EfAjPX8E3/owXilFj5bLBEpl6eYJg+i+RF+8+zlut45OXqrMO 1s5pvgwglq6kzZw70Wt8PavxP9ppcp2kwy82rNQbDLaskfkGcsV2o9QnJzcNgIIC 1Kr7jf1iqF7qJC8/F9F3cg3YBvzz2fozdaX1nWigdus9QsXq00ZRjByR1rd43ePH gLEoJVzD95djWYP/JRiv65ZTqdDY6dMMsHwlfSfFPa9/w2uoZsjFaJmg8Eoj0K9o 4f2RHzIioizY9pLPWqRh4D3rOBOlTKMZyiRrYh4gdVpYWfS6D0Ae5zZx67r0VFje MdVM3AUUyADwsHIE3+MBRu/OAeYnMDHIMHRlXON/YNXwYpRYMI9deS2y+kkYcxhY ttl+B88UBRD0MR5twmCJ2OAAMe5WNtq0jlhuAGTnPJpDHSSd6fa/sm8Csoj1gdqr ZSTh0JUy6RlECePeVHW+FCEBDPsWfM05pHY8p73KZrS3c4QWPXsH5GmnxGOcOuQh Az1agFN4gqebFTG6l1K40CBSf7DWw38aYw+sFZWLJLM5/eSQtIaYgKhMwOu1N0Cp oVgtwRVWQ0x/l3B4WNfgMHDq5xigD+ElGcvhPhRepzHPH4dZJxLYlpHDSV31o6k+ Myi3cewJzt+JVL4KN1yf =u5fy -----END PGP SIGNATURE----- --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
