1.1

Table Of Contents
Host Machine Requirements
Requirements for each host:
A supported Java SE installation.
File system that supports long le names.
Adequate per-user quota of le handles (ulimit for Linux)
TCP/IP.
System clock set to the correct time.
For each Linux host, the hostname and host les must be properly congured. See the system manpages
for hostname and hosts.
Time synchronization service such as Network Time Protocol (NTP).
Note: For troubleshooting, you must run a time synchronization service on all hosts. Synchronized time
stamps allow you to merge log messages from different hosts, for an accurate chronological history of a
distributed run.
Increase Unicast Buffer Size on Linux Platforms
On Linux platforms, execute the following commands as the root user to increase the unicast buffer size:
1.
Edit the /etc/sysctl.conf le to include the following lines:
net.core.rmem_max=1048576
net.core.wmem_max=1048576
2.
Reload sysctl.conf:
sysctl -p
Disable SYN Cookies on Linux Platforms
Many default Linux installations use SYN cookies to protect the system against malicious attacks that ood
TCP SYN packets. The use of SYN cookies dramatically reduces network bandwidth, and can be triggered by
a running SQLFire distributed system.
If your SQLFire distributed system is otherwise protected against such attacks, disable SYN cookies to ensure
that SQLFire network throughput is not affected.
To disable SYN cookies permanently:
1.
Edit the /etc/sysctl.conf le to include the following line:
net.ipv4.tcp_syncookies = 0
Setting this value to zero disables SYN cookies.
2.
Reload sysctl.conf:
sysctl -p
Client Requirements
SQLFire supports two JDBC drivers: a thin client JDBC driver and a peer JDBC driver. SQLFire server instances
and the peer driver are supported only with Java SE 6. You can download Java from
http://www.oracle.com/technetwork/java/javase/downloads/index.htm.
vFabric SQLFire User's Guide16