Problem Note 49356: SAS® Stored Process servers that have been load-balanced across multiple machines in a certain do not distribute connections correctly
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If SAS Stored Process servers are load balanced across multiple machines in a certain way, connections are not distributed correctly according to the cost algorithm. The result is an uneven distribution of connections. That is, all of the connections on one of the machines in the cluster are used before any connections are sent to the other machines.
Essentially, there are two ways in which to configure SAS Stored Process servers so that they are load balanced across multiple machines. These two methods are shown below as they would appear in SAS® Management Console. In the first of these two configurations, load balancing is not handled properly. In the second case, it is handled correctly.
Method 1: This method does NOT handle load balancing properly:
Logical Stored Process ServerMethod 2: This method DOES handle load balancing properly:
Logical Stored Process ServerIf you use Method 1, the load will not be balanced evenly across the different machines. In this configuration, when a request comes in to the load–balanced cluster, the cost algorithm is used to determine which machine should handle this request. If the algorithm determines that the second machine is the best host on which to run the load, then the connection load is not reset. This behavior causes connections on the newly selected host to be compared to the lowest loaded connection on the previous host. As a result, the cost algorithm does not send any connections to the servers on Machine 2 until all of the connections on Machine 1 are used.
This behavior can be particularly problematic in a SAS® Customer Intelligence installation because the stored process servers are limited to only one client.
If you use Method 2, you should not encounter any problems with how load balancing is handled.
Click the Hot Fix tab in this note to access the hot fix for this issue.
Operating System and Release Information
| Product Family | Product | System | SAS Release | |
| Reported | Fixed* | |||
| SAS System | SAS Integration Technologies | Linux for x64 | 9.3 TS1M2 | 9.4 TS1M0 |
| Linux | 9.3 TS1M2 | 9.4 TS1M0 | ||
| HP-UX IPF | 9.3 TS1M2 | 9.4 TS1M0 | ||
| 64-bit Enabled Solaris | 9.3 TS1M2 | 9.4 TS1M0 | ||
| 64-bit Enabled HP-UX | 9.3 TS1M2 | 9.4 TS1M0 | ||
| 64-bit Enabled AIX | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Windows Vista for x64 | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Windows Vista | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Microsoft Windows Server 2008 | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Microsoft Windows Server 2003 for x64 | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Microsoft Windows Server 2003 Standard Edition | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Microsoft Windows Server 2003 Enterprise Edition | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Microsoft Windows Server 2003 Datacenter Edition | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Microsoft® Windows® for x64 | 9.3 TS1M2 | 9.4 TS1M0 | ||
| z/OS | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Windows 7 Ultimate x64 | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Windows 7 Ultimate 32 bit | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Windows 7 Professional x64 | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Windows 7 Professional 32 bit | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Windows 7 Home Premium x64 | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Windows 7 Home Premium 32 bit | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Windows 7 Enterprise x64 | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Windows 7 Enterprise 32 bit | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Microsoft Windows XP Professional | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Microsoft Windows Server 2008 for x64 | 9.3 TS1M2 | 9.4 TS1M0 | ||
| Solaris for x64 | 9.3 TS1M2 | 9.4 TS1M0 | ||
A fix for this issue for Threaded Kernel IOM 9.3_M1 is available at:
https://tshf.sas.com/techsup/download/hotfix/HF2/I23.html#49356| Type: | Problem Note |
| Priority: | high |
| Date Modified: | 2013-03-12 09:29:46 |
| Date Created: | 2013-03-05 13:57:28 |