FOREACH array_expression AS value
statements...
ENDFOR
FOREACH array_expression AS key => value
statements...
ENDFOR
The first form loops over the array given by array_expression. On each loop, the value of the current element is assigned to value and the internal array pointer is advanced by one (so on the next loop, you'll be looking at the next element). The second form does the same thing, except that the current element's key will be assigned to the variable key on each loop. This form works only on associative arrays and objects.
APPEND FROM <table-name>Before when appending into a shared Recital table each new row was locked along with the table header, then unlocked after it was inserted. This operation has now been enhanced to lock the table once, complete inserting all the rows from the table and then unlock the table. The performance of this operation has been increased by using this method. All the database and table constraints are still enforced.
- For building shared libraries on the MAC the following need to be set
-
- The shared library file extension should be .dylib
- The compile flag is -dynamic
- For accessing the shared libraries at runtime
-
- DYLD_LIBRARY_PATH needs to be set to the location of the shared libraries
- Useful utilities for shared library support
-
- The following command will display the table of contents of the dynamically linked library
otool -TV sharedlibraryfile.dylib
try
open database southwind
catch
die("Cannot open database, please try later.")
endtry
The Recital Oracle Gateway requires the Oracle libclntsh.so shared library. If this file is unknown to ld.so.conf, add it using the ldconfig command.
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
DB_SAMBA=YES ;export DB_SAMBA
preserve case = nodefault case = lowermangle case = yes
oplocks = False
share modes = no
COPY DATABASE <name> TO <name> [ IF [ NOT ] EXISTS ]This command is used to copy an existing database to a new database. By default an error will be returned if the target database already exists. Specifying the optional IF NOT EXISTS keywords no error will be returned if the target database already exists. If the optional IF EXISTS keywords are specified and the target database already exists, then it will be removed before the copy. Both the databases must be closed before they can be copied.