Sun Java System Application Server 9.1 High Availability Administration Guide


In general, you can install HADB on the same system as Application Server (co-located topology) or on separate hosts (separate tier topology). For more information on these two options, see Chapter 3, Selecting a Topology, in Sun Java System Application Server 9.1 Deployment Planning Guide.

You must install the HADB management client to be able to set up high availability with the asadmin configure-ha-cluster command. When using the Java Enterprise System installer, you must install an entire HADB instance to install the management client, even if the nodes are to be installed on a separate tier.

HADB Installation

On a single or dual CPU system, you can install both HADB and Application Server if the system has at least two Gbytes of memory. If not, install HADB on a separate system or use additional hardware. To use the asadmin configure-ha-cluster command , you must install both HADB and Application Server.

Each HADB node requires 512 Mbytes of memory, so a machine needs one Gbyte of memory to run two HADB nodes. If the machine has less memory, set up each node on a different machine. For example, you can install two nodes on:

Default Installation Directories

Throughout this manual, HADB_install_dir represents the directory in which HADB is installed. The default installation directory depends on whether you install HADB as part of the Java Enterprise System. For Java Enterprise System, the default installation directory is /opt/SUNWhadb/4. For the standalone Application Server installer, it is /opt/SUNWappserver/hadb/4 .

Node Supervisor Processes Privileges

The node supervisor processes (NSUP) ensure the availability of HADB by exchanging “I’m alive” messages with each other. The NSUP executable files must have root privileges so they can respond as quickly as possible. The clu_nsup_srv process does not consume significant CPU resources, has a small footprint, and so running it with real-time priority does not affect performance.

Note –

The Java Enterprise System installer automatically sets the NSUP privileges properly, so you do not need to take any further action. However, with the standalone Application Server (non-root) installer, you must set the privileges manually before creating a database.

Symptoms of Insufficient Privileges

If NSUPs do not have the proper privileges, you might notice symptoms of resource starvation such as:


If NSUP cannot set the real-time priority errno is set to EPERM on Solaris and Linux. On Windows it issues the warning “Could not set real-time priority”. The error is written to the ma.log file, and the process continues without real-time priority.

Setting real-time priorities is not possible when:

ProcedureTo Give Node Supervisor Processes Root Privileges

  1. Log in as root.

  2. Change your working directory to HADB_install_dir/lib/server.

    The NSUP executable file is clu_nsup_srv .

  3. Set the file’s suid bit with this command:

    chmod u+s clu_nsup_srv

  4. Set the file’s ownership to root with this command:

    chown root clu_nsup_srv

    This starts the clu_nsup_srv process as root, and enables the process to give itself realtime priority.

    To avoid any security impact, the real-time priority is set immediately after the process is started and the process falls back to the effective UID once the priority has been changed. Other HADB processes run with normal priority.