My advice on JVM heap tuning, keep your fingers off the knobs!
Just in the last few months I've been seeing an increase in the number of people seeking advice in the forums on how to tune garbage collection and/or size Java heap. While it is encouraging to see...
View ArticleMixing long and short lived objects
When blog-city was in it’s infancy Alan Williamson wasn’t using a lot of hardware to support the system (new stuff was in the mail). In fact, it was running on a single PIII 850MHz PC with 512M of ram...
View Articleverbose gc logging
I ran into an interesting question regarding gc logging in production. The production team was hesitant to turn on gc logging because the claimed that it created a significant drag on performance. GC...
View Article100% CPU with output from jstat
A question about why a Java process was running at 100% recently showed up in the Java Posse forum. The author of the question had the insight to take thread dumps and use a little known but useful...
View ArticleWhy do I have this long GC pause?
Just recently I ran into a question as why a collection took 9 seconds to complete. It's a question that comes up reasonably often and how to answer it is a topic that I give considerable attention to...
View ArticleGC Log webinar
I'm really looking forward to presenting the performance tuning course in Crete next week. This will be the second time that I've used Heinz's wonderful facilities and it marks the first time we will...
View ArticleProposed change to the GC efficiency calculation
The industry has pretty much settled on the calculation for GC efficiency to be 1 - ( total GC pause time / application run time). It's a reasonable measure of how much CPU the parallel collectors are...
View ArticleMemory leak in Eclipse 4.2.2
It's been a while since I've blogged anything. So much has happened. I've started a new performance tooling company JClarity. Couple this with running Kodewerk and it's been a very hectic year to say...
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