Paul Leclerc <[EMAIL PROTECTED]> writes: > Don't forget that by default, Java caches IP addresses for DNS > lookups. See this link for more information: > http://java.sun.com/j2se/1.4.2/docs/guide/net/properties.html and > look at both networkaddress.cache.ttl and sun.net.inetaddr.ttl
That looked very promising but it doesn't seem to be helping. In $JAVA_HOME/jre/lib/security.java.security I set networkaddress.cache.ttl=1 and see it querying my dnscache often, whereas before it queried it only once. That's good. However, it's only trying one of the addresses in DNS for that name. The name I configure jmeter to test is "cluster" which evaluates to two different IPs both with 1s TTL; I have it use 5 threads, and loop 5 times, with a 30-second ramp-up-time. I do see my DNS being queried repeatedly for that name, but jmeter only hitting one. Interestingly, quitting and re-running the "jmeter" startup script has no effect: it keeps returning to the same target host address. My dnscache is documented to return a list of addresses in random order for each query. The law of probabilities says it should get them both 50% of the time, this is about 10 out of 10 times it gets the same one. (Is it suspicious it's the lower of the two addrs?). Also, if I shut down the tomcat on the target it's picked, jmeter appears to hang. Is it not written to try other addresses in the list of addresses it got for the target's name? I don't have the code here to look. Perhaps this wasn't a design goal. Any thoughts? I can't test the robustness of my tomcat-4 session clustering if my test tools won't try alternate addresses. Thanks again. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
