![]() |
![]() HP OpenVMS Systemsask the wizard |
![]() |
The Question is: Is there a lot of system overhead when using TCP/IP socket IPC between 2 processes on the same local machine. What I mean is , is it justifiable (and efficient) to use sockets in place of mailboxs or other local IPC methods on VMS. The Answer is : There is no certain answer without rather more detail of course, but the OpenVMS Wizard would not expect significant intra-node performance differences among the various inter-process communications techniques, once the initial connections (for the connection-oriented protocols) are established. (Connectionless mechanisms can have advantages over connection-oriented protocols for certain communications traffic.) Within an OpenVMS Cluster, the OpenVMS Wizard would typically first look at using ICC (IntraCluster Communications) and IP. One obvious reason for choosing a network protocol (or even middleware package) would involve using source code that would be independent of the particular communications patterns, allowing for possible future changes to the application -- permitting future expansion to multiple cluster members or multiple networked systems. A secondary reason might involve simple familiarity and overall expedience: programmer familiarity with networking techniques, and the relative ease of avoiding various software inefficiencies through the addition of hardware. In other words, using techniques and tools familiar to the programmers and hardware upgrades may well be cheaper than using more efficient coding techniques and tools. And it may be easier to evaluate the entire application system -- either in prototype form, or even once the baseline system is running -- for any required performance tuning or for hardware upgrades, if any are even required.
|