Hello
I also had to face this kind of situation where the network latency was impacting the application performance after migrating from single LPAR to separate LPARs for app server and DB server.
If your two LPARs are on the same physical machine (and you don't plan to have them on separate physical machines), then I advise you to use a virtual network between them, I mean one single VLAN (no routing !), you should definitely avoid the additional latency of the software network virtualization performed by the SEA : if you stay on same VLAN and same physical machine then all network communication between both LPARs will go through the virtual network managed by the hypervisor without needing the cost of transferring packets from/to virtual network to/from physical network by the SEA.
Another good solution is to use SR-IOV network adapters (use vNIC if you want to be able to implement LPM), as it provides hardware network virtualization which is much more performant than SEA and gives better latency.
In my case the app running on the servers was badly coded with lots of big loops retrieving data one row at a time in a very inefficient manner so that the network latency was big compared to the queries execution time.
In any case, if you want maximum performance, you have to minimize the network path length between the APP and the DB : avoid routing and software virtualization where possible.
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Fabrice PLATEL
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Original Message:
Sent: Wed August 25, 2021 06:50 PM
From: arnulfo martinez ruiz
Subject: 4GL application performance over TCP / IP connections
Hello community,
I have this situation:
1. We are migrating database and applications (4GL) from a power 7 to a power 9.
2. In the previous architecture (Power 7) the applications (4GL) were running on the same LPAR as the database.
3. In the new architecture it is proposed to separate the two layers, an LPAR for the database and another LPAR for applications (4GL)
4. The tests that have been carried out show that the same application (4GL) executed over a TCP / IP connection (onsoctcp) has a delay greater than thirty percent.
5. We have done tests with the environment variable FET_BUF_SIZE (4K / 8K / 16K / 32k / 64K, 128K, 256K) and the times have not improved much.
I appreciate your recommendations on the network or in the configuration of the 4GL client environment
Thank you
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arnulfo martinez ruiz
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#Informix