telstone's questions

Does anyone know of a ppa / repo that will install tomcat7. I know I can install from source but I'd rather if possible use a PPA/Repo.

I found a nice one for suncoughoracle-java but there does not seem to be anything for tomcat7 as of yet.

I've installed tomcat6 without issue and like the layout. We are in the process of certifying our application for tomcat7 and I would like to have a solid production ready setup.

Here is the the cheat for installing suncoughoracle-java on a clean Ubuntu LTS server:

sudo apt-get install python-software-properties
sudo add-apt-repository ppa:sun-java-community-team/sun-java6
sudo apt-get update
sudo apt-get install sun-java6-jdk

ubuntu@ubuntu:/etc/apt$ java -version
java version "1.6.0_24"
Java(TM) SE Runtime Environment (build 1.6.0_24-b07)
Java HotSpot(TM) 64-Bit Server VM (build 19.1-b02, mixed mode)

We are getting ready to make a major revision in our Web Application architecture which currently is running on JBoss 4.2. At first we were looking at moving from 4.2 to JBoss 6 but after some research tomcat may be a better solution for us.

My first question is their anything that JBoss can do that tomcat cannot do assuming you are using the correct plugins. We do not really use EJB's in our solution and it would appear there are simple plugins for web services, JMX and other features.

Tomcat appears to have much better support, faster upgrade cycles and many, many books.

Since there is less to the system it also seems much easier to support from an admin point of view.

What am I missing?

The main features we want to enable are better clustering support and session replication / persistence.

We will consider other application servers as well such as Glassfish / Geronimo.

quote form a web article:

Apache Tomcat is the world’s most widely used web application server, with over one million downloads per month and over 70% penetration in the enterprise datacenter. Tomcat is used to power everything from simple one server sites to large enterprise networks.

I have found several articles by academics on how to setup JBoss clustering but I would like some opinions from people how have REALLY done it.

First off in every serious article I've come across I have read that you should NEVER use the farm directory in production! As a result we have setup a series of scripts that will copy over a fresh ear to each of the 5 to 10 servers in a cluster via SCP. While this works it does have some time / scaling issues as deployments get bigger. As a result we have started to test setting up NFS mounts. So far in initial testing this seems to work quite well. Has anyone deployed like this before?

The next issue is web session clustering. Currently we deploy a hardware load balancer with sticky session enabled. However we are not replicating session and if a server goes down or is rebooted all users will get a session time out. What is the best way to work around that issue. If possible I would prefer to persist the session data down to the database or to an out of process JVM instance. I have seen rumblings of a technique to save session down to the DB layer but have never been able to get it working. Anyone have this working?

Finally if possible I would like to replace the need for a hardware load balancer at least for smaller deployments with a simple apache server. We have been using the AJP/mod_proxy to work through this but it would appear that mod_cluster may be the way to go in 5.x version of JBoss. Has anyone worked with this in a production setting and can you speak to its stability / performance (http://www.jboss.org/mod_cluster)

thanks in advance

Originally when we began moving to db2 LUW we ran into some issues where our tables were too big to fit into the default 4K table space. As a result of "pressure" to get it done we just went with a 32K default table space and put ALL of our tables there.

What impact would that have if any? I talked to one person who said that it would possible make out database MUCH larger than it needed to be. Is that true? What about memory? Would there be any benefit to moving the smaller tables back to a 4K table space? I have looked around in forums and what not but cannot seem to find a good answer.

We have a large Xen deployment running on both RHEL and CentOS and have recently started looking at KVM since this is where it looks like the future of VM's are on Linux.

We can load the server and get everything running without an issue. However when we load up a new one with JBoss (4.2 Community edition, Sun JDK 6) and load a large EAR the server goes a little crazy. The %sy will jump to 80-99% and just hang for large periods of time we see a similar jump in %us on the host machine. We though at first this might be I/O as it seems to happen at start of JBoss but then would "cool down" after everything got loaded. We did some tests by extracting some large tar.gz files and using jar -xvf on the ear but could not re-create.

Then we starting thinking this might be some type of memory access issues. We loaded a c-program that would generate a lot of memory activity and sure enough we saw the spikes again. Not as high mind you but we did see it jump. We then wrote a small java program to do the same thing and sure enough we saw it jump again.

Any thoughts on what might be causing this? Is this just the way KVM works?

As a side note we do NOT see this behavior on any other setup. Xen, VMWare and/or native iron. The system does seem a bit slower than our Xen / VMware ones.

We are setting up a new database system and have 15 drives to play with (+2 on-board for the OS).

With a total of 15 drives would it be better to setup all 14 as one RAID-10 block (+1 hot spare) OR split into two RAID-10 sets one for Data (8 disks) and one for logs/backups (6 disks).

My question boils down to the following: is there a specific point where having more drives in a RAID-10 setup will out preform having the drives broken into smaller RAID-10 sets.