$ lsof | grep db.exe | grep accounts db.exe 16897 john 6uw REG 253,0 20012 3413872 /usr/recital100/qa/accounts.dbf db.exe 16897 john 7u REG 253,0 4176 3413885 /usr/recital100/qa/accounts.dbxIf you want to check for locks you can use lslk, for example;
$ lslk | grep db.exe | grep accounts db.exe 16897 253,0 3413872 20012 w 0 0 0 12319 0 /usr/recital100/qa/accounts.dbfIf you don't have lslk installed you can install it with one of the updaters, for example on redhat linux:
$ yum update lslk
I am pleased to finally report that the Centos release of Redhats 5.3 has been built and is available for download from http://www.centos.org/
The highlights of this release can be found at the following URL: http://www.redhat.com
The main areas of interest in my opinion excluding critical secirty fixes are:
- Updated hardwaresupport support for the new Intel Core i7 (Nehalem) chips
- Beefed up virtualiseation support increasing CPU and Ram limits of Virtual machines.
- Inclusion of the fully open sourced OpenJDK. This makes Red Hat Enterprise Linux 5.3 the first enterprise-ready solution with a fully open source Java stack when combined with JBoss Enterprise Application Platform.
For those who already have Centos 5.2 installed you can simply receive the update via Yum.
Before you do the following, check that you do not have 3rd party repo's and the Centos-testing repo enabled.
You can display the currently enabled repo's using the following command.
$ yum repolist
Then as root at the prompt type:
$ yum update
STRERROR()
Syntax
STRERROR( [ <expN> ] )Description
The STRERROR() function returns a string describing the last operating system error message. If the optional error number is specified then the related operating system error message will be returned.Example
mqdes=mqcreate("/myqueue", 2)
if (mqdes < 0)
messagebox(strerror()+",errno="+alltrim(str(error())))
return
endif
rc = mqsend(mqdes, "Test message")
if (rc < 0)
messagebox(strerror()+",errno="+alltrim(str(error())))
return
endif
mqclose(mqdes)
The 64bit port of Recital requires these libraries to allow access to 32bit Xbase and C-ISAM data files which are 32bit.
If you do not have these libraries installed you will either get a "can't find db.exe" or an "error loading shared libraries" when trying to run or license Recital.
Installing the ia32 shared libraries
Redhat EL 5 / Centos 5 / Fedora 10
-
Insert the Red Hat Enterprise Linux 5 Supplementary CD, which contains the ia32el package.
-
After the system has mounted the CD, change to the directory containing the Supplementary packages. For example:
cd /media/cdrom/Supplementary/
-
Install the ia32el package:
rpm -Uvh ia32el-<version>.ia64.rpm
yum install ia32el
Ubuntu / Debian
sudo apt-get install ia32-libs
- New MD5( expC ) function to calculate an MD5 crypto key from any character expression
- New MD5FILE( expC ) function calculates an MD5 crypto key for a given filename. If the filename is a pattern e.g *.* it will calculate the key across all files matching the pattern
- New mod_recital.so available for using Recital Web on linux x86_32
- New mod_recital64.so available for using Recital Web on linux x86_64
USE accounts INDEX on account_no TAG outstanding FOR balance > 0 EXPLAIN SELECT * FROM accounts WHERE balance > 0 Optimized using for condition on tag 'OUTSTANDING'
When you start the loadbalancer.org appliance you will see the following:
Default login:
Username: root
Password: loadbalancer
Access to webclient from an external client is:
http://192.168.1.129:9080
http://192.168.1.129:9443
You can access the web administrator using the IP and ports described onscreen.
For the sri lanka porject we are looking for performance and the network diagram indicates we are happy to have the cluster on the same subnet as the rest of the network.
Direct routing is the fasted performance possible, it has the advantage over NAT that the Loadbalancer does not become a bottleneck for incoming and outgoing packets. With DR the loadbalancer simply examines incoming packets and the servers to route the packets directly back to the requesting user.
The web interfaceis the only way to fully configure the loadbalancer vm. The console tool lbwizard will get it initiallised and any further configurations can then be done via the webinterface.
Using lbwizard for the Sri lanka configuration follow these steps.
On the first Loadbalancer:
//Start
Is this unit part for a HA Pair?
YES
Have you already setup the Slave?
NO
Is this a one-armed configuration?
YES
Enter the IP Address for the interface eth0?
Enter IP address you wish to be assigned to the SLAVE loadbalancer.
Enter the netmask for interface eth0?
Enter netmask for the subnet.
Enter the Floating IP adrress?
Enter the IP address that will be IP assosiacted the the HA-pair of loadbalancers.
//Finish
On the 2nd loadbalancer VM, run the lbwizard.
//Start
Is this unit part of an HA-Pair?
YES
Have you already set up the Slave?
YES
What is the slave units UP address?
Enter the IP which you entered when configuring the other loadbalancer VM.
Is this a one-armed configuration?
YES
Enter the IP Address for the interface eth0?
Enter the IP that will be assigned to the MASTER loadbalancer
Enter the netmask for interface eth0?
Enter the subnet netmask.
Enter the Floating IP address?
Enter the IP address that will be IP assosiacted the the HA-pair of loadbalancers.
Enter the address of the default gateway?
Enter the deafult gateway for the subnet.
Enter the IP of the nameserver?
Enter the dns server.
Enter the port for the first Virtual server?
Enter 22 for ssh
Enter the IP address of the first real server?
Enter the real IP of the first appserver
//Finish
Now this is complete we need to go to the web admin interface to configure the 2nd Real Server. As the lbwizard program will only allow you to configure 1 real server.
Now login to the web admin using the default password:
username: loadbalancer
password: loadbalancer
Note: Connect to the IP you have now set for your master loadbalancer
Goto the edit configuration tab
Now click add a real server:
Enter a label
IP address of the server plus the port of the service i.e. 192.168.1.125:22
Edit Configuration -> Virtual Servers
persistancte -> NO
Scheduler-> LC
LC - Least-Connection: assign more jobs to real servers with
fewer active jobs.
Service to check -> custom1
Check port -> 22
Forwarding Method -> DR
Feedback Method -> Agent
Arp Problem when using DR
Every real server must be configured to respond to the VIP address as well as the RIP
address.
You can use iptables (netfilter) on the real server to re-direct incoming packets destined for the virtual
server IP address.
This is a simple case of adding the following command to your start up script (rc.local):
//replace 10.0.0.21 with the Virtual Server IP
iptables -t nat -A PREROUTING -p tcp -d 10.0.0.21 -j REDIRECT
chkconfig iptables on