Upcomming tech meetups in Moscow



Here is announcing of upcoming tech meetups (more...)

How to simulate Coherence node failure in JUnit test

Recently, I was working on renewed version of Coherence data loss listener. New version provides simple utility to attach partition loader to any cache. Such partition loader is guaranteed to be called for every partition of newly created cache or after partition has been lost. Unlike CacheStore, partition loader (more...)

Remote code execution in Java made trivial

SSH offers a very convenient way to execute shell scripts remotely. Code like

ssh myserver.acme.com << EOC
cd $APP_HOME
./start_my_stuff.sh
EOC

are fairly easy to write and read.

But while remote execution itself is easy, writing actual distributed code is total mess.

I’m a Java guy. I (more...)

Coherence 101, Beware of cache listeners

Cache events facility is a quite useful feature of Oracle Coherence. For example, continuous queries and near cache features are build on top of cache event system.
Unfortunately it could be also abused easily. In particular, they are noticeably bad at scale unless you are very careful.
Please note. This (more...)

Safepoints in HotSpot JVM

Term Stop-the-World pause is usually associated with garbage collection. Indeed GC is a major contributor to STW pauses, but not the only one.

Safepoints

In HotSpot JVM Stop-the-World pause mechanism is called safepoint. During safepoint all threads running java code are suspended. Threads running native code may continue to run (more...)