AIX: IBM’s AIX Unix operation system.
Create Users
If the source, target or repository databases are on IBM UDB, you will need to use operating system user id's as the database id's. Your AIX system administrator (root authority) can create these users for you using the mkuser command.
If you are using IBM UDB, additional AIX users may be required. IBM UDB differs from Oracle in that schemas can be (and often are) created independently of users. When a user is created in Oracle and that user creates objects, the objects are associated with the users schema. In IBM UDB, a schema can be created without a corresponding user. To access objects in that schema, you must reference the objects using <schema name>.<object name>. This creates additional work when building PowerCenter mappings and/or sessions because schema overrides are required if you use a user that does not correspond to the schema. To avoid this hassle, it is advisable to create AIX users with the same names as the schemas you need to access. These users should then be given select, insert, update and delete authority on all objects in their respective schemas. If you want to use the truncate table session option to truncate tables prior to load, then the user also needs control authority on the tables.
Debugging Core Dumps
Core dumps are created when errors occur in the PowerCenter code due to environmental issues or software bugs.
Follow these steps to debug a core dump:
- Ensure you are in the directory in which the core dump was created. Most likely the Informatica server directory
- Make a backup of the core file using the following command:
cp core core1
- Give full permissions to the core file using the following command:
chmod 777 core1
- Ensure you have a suitable utility to debug the core dump. It is most likely dbx. Use the following command to ensure dbx can be found:
which dbx
This will return the location of the dbx command, if one is found in the user's path. It is likely to be located at usr/bin/dbx. If no suitable debug utility is found, contact Informatica tech support.
The following steps assume you are using the dbx utility.
You may now run the dbx utility. The syntax is to call the debug utility, the application that created the core dump and the core dump itself. Use the following example.
/usr/bin/dbx -d 500 ./pmserver ./core1
- If applied properly, you will see the AIX prompt change to (/usr/bin/dbx).
- Type where. You will see the output of the core dump. Copy this output and send it to tech support.
- You are now finished and can type quit to exit the utility.
Cleaning Up Memory
Some processes running on AIX leave libraries open after being shut down. This may interfere with installing applications within the Informatica suite. You can use the slibclean utility to clean up memory on an AIX machine. It is standard on most AIX environments. Simply use the following command to run it: /usr/sbin/slibclean
Monitoring System Performance
If PowerCenter sessions are running slowly, you need to identify where the bottleneck is in the process. It is usually in the source, the target, or the Data Transformation Manager (DTM). Source and Target processes only exist where the source or target are databases. The process names will depend on the database type.
The ps command is one tool to monitor CPU usage on the AIX system. The ps command has many available options. The following use of the command sorts the output by CPU usage.
/usr/bin/ps aux | tail +2 | sort -k 1.15,1.19nr
Another useful version of this command allows you to see paging activity and status of processes, in addition to CPU and memory consumption.
/usr/bin/ps vg
To get a system activity report, you can use the sar command. To see five samples of CPU usage in two second intervals use: /usr/sbin/sar 2 5
On a multi-process system you can get a by-processor breakdown by using the –P flag.
/usr/sbin/sar -P ALL
The vmstat command offers another way to look at memory and CPU usage. To see system snapshots at two second intervals use: /usr/bin/vmstat 2 5
When interpreting the results of the vmstat command, be careful to understand the first line of the report. The first line gives the average since the operating system was last rebooted; it is not a current snapshot. The pi and po columns in the report show the pages in and pages out. If po is not low, then the system may well be doing excessive paging. You can see the CPU usage by user, system, idle and I/O wait under the CPU heading. If the percentage I/O wait is high, then your system may have disk-read or -write bottlenecks.
If you feel that your system may be disk bottlenecked, then you can use the iostat command. To see disk usage snapshots at two second intervals use: /usr/bin/iostat -d 2 5
As with the vmstat command, be careful when interpreting the output from the first interval; it is an average since the operating system was last rebooted rather than a snapshot. Because the output from iostat is presented on a per-disk basis, it can be useful in demonstrating some database issues, like tables and indexes being in the same tablespace, or tablespaces not being distributed across multiple disks.
Network Troubleshooting
Occasionally, there are cases where you experience problems connecting to remote databases as source or target, or issues with pre or post-session ftp connections. The following paragraphs describe some AIX commands that can help you to troubleshoot these issues by testing connections between machines.
Ping is used to verify that you can connect to a remote machine. To test a connection with 10 packets use: /usr/sbin/ping <remotehost> -c 10
If you omit the -c option, ping will send packets until you hit ctrl-c.
To see the path the network is sending your packets, use the traceroute command. Its syntax is: traceroute <remotehost>
Traceroute will return a response from every gateway between the local machine and the remote, which lets you know the route along which your packets are being sent. If there is a network issue at any point (such as a routing problem, or a machine down), then the output will report a failure at that point.
To check the entries about a particular machine in the DNS server, use the nslookup command. Nslookup has many options but here are a couple that are commonly used.
/usr/bin/nslookup <hostname> will return the domain name and IP address of the hostname (e.g., if the hostname is central, this command returns central.Informatica.com and 10.1.32.38).
To check whether a particular name is a hostname, domain, or other use:
/usr/bin/nslookup -querytype=ANY <name>
This query also returns the Statement of Authority, name server, mail exchanger, and host Internet address information where applicable.
When troubleshooting connections to the pmserver process (the PowerCenter process) or in PowerCenter 6.x to the pmrepserver process (the Repository Server process), use the following command to view the state of all active Internet sockets:
/bin/netstat -af inet
