Network Setup - interconnect network device type

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This test shows the impact on network traffic throughput when using a HiperSockets connection for network traffic, instead of a 1 Gb or 10 Gb OSA card.

As shown in Cluster file system OCFS2 versus Oracle Automatic Storage Management, the network traffic over the interconnect is very much higher than the communication traffic with the clients. Therefore, the bandwidth of the underlying network device type is an important performance parameter.

Figure 1 shows the improvement of using HiperSockets compared to a 10 Gb OSA card or a 1 Gb OSA card.
Figure 1. Improvement when using HiperSockets or the Interconnect versus 1 Gb or 10 Gb OSA card
Bar graph of the improvement in transaction throughput when using a HiperSockets connection, compared to a 10 Gb Ethernet and 1 Gb Ethernet connection. The x-axis has three sets of bars for representing 40, 60, and 80 users. Each set consists of two bars, one for HiperSockets compared to the 10 Gb Ethernet and one for HiperSockets compared to the 1 Gb Ethernet. The y-axis is the improvement when using HiperSockets expressed in percentage, ranging from 0% to 12%. For the case with 40 users, the values are 8.1 % improvement for the 10 Gb Ethernet and 11.2 % improvement for the 1 Gb Ethernet. For the case the 60 users, the value is an 8.1% improvement for the 10 Gb Ethernet. For the case with 80 users, the improvement is 11% for the 10 Gb Ethernet. For the cases of 60 and 80 users, the 1 Gb Ethernet was not sufficient for processing the workload.

Observation

This graph shows the relative improvement in transactional throughput when HiperSockets is compared with two other types of devices used for the Cluster Interconnect. With 40 users, the improvement is 8% when compared to a 10 Gb OSA card and 11% when compared to a 1 Gb OSA card. At higher workload levels, the advantage of the HiperSockets connection increases to 11% when compared to a 10 Gb OSA card.

Conclusion

HyperSockets are the best choice for the Oracle RAC interconnect. It is possible to use HiperSockets when the server nodes are on the same physical IBM® System z®. The second choice would be to use a 10 Gb OSA card. As shown here, the use of a 10 Gb OSA connection does not necessarily require a full 10 Gb infrastructure with switches, and so forth. A direct coupling of two OSA ports with a standard cable makes the connection in point-to-point mode, which additionally reserves the full bandwidth for the interconnect and avoids any interaction with other network workloads, ensuring a constant response time.

In combination with the 1 Gb OSA connection a new wait event occurs, wait event cr request retry, indicating that the 1 Gb interconnect is not sufficient for the workload processed.