From Software journal blog an extract. Clustering has a formal meaning. A cluster is a group of resources that are trying to achieve a common objective, and are aware of one another. Clustering usually involves setting up the resources (servers usually) to exchange details on a particular channel (port) and keep exchanging their states, so … Read more
MPI was deisgned tightly-coupled compute clusters with fast, reliable networks. Spread and ØMQ are designed for large distributed systems. If you’re designing a parallel scientific application, go with MPI, but if you are designing a persistent distributed system that needs to be resilient to faults and network instability, use one of the others. MPI has … Read more
The locality level as far as I know indicates which type of access to data has been performed. When a node finishes all its work and its CPU become idle, Spark may decide to start other pending task that require obtaining data from other places. So ideally, all your tasks should be process local as … Read more
You could set PHP to handle the sessions in the database, so all your servers share same session information as all servers use the same database for that. A good tutorial for that can be found here.
I can think of a couple of possible explanations: Other applications on your system are using so much memory that there isn’t 300Gb available right now. There could be a resource limit on the per-process memory size. You can check this using ulimit. (Note that according to this bug, you will get the error message … Read more
I have found this article on the subject: http://www.tenereillo.com/GSLBPageOfShame.htm Basically if you do not require long lasting sticky sessions you can configure your DNS servers to return multiple A records (IP addresses) for your website. Web browsers are smart enough to try all the addresses until they find one that works.
Found the answer buried in an old supercluster.org thread: qselect -u <username> | xargs qdel Worked flawlessly.
I’ve looked extensively at Zookeeper/Curator, Eureka, etcd, and consul. Zookeeper/Curator and Eureka are in many ways the most polished and easiest to integrate if you are in the Java world. Etcd is pretty cool and very flexible, but It is really just a HA key store so you would have to write a lot of … Read more
As of Python >=3.2, os.makedirs() can take a third optional argument exist_ok: os.makedirs(mydir, exist_ok=True)