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Daniel Nashed


Tune Domino HTTP connections

Daniel Nashed  22 May 2023 09:49:47

When performing performance tests with a new tool I wrote based on LibCurl, I noticed many connections in network TIME_WAIT.

It turned out I had persistent connections enabled. But the value was set to low on the server.

Other servers with higher values, had much less TIME_WAIT sessions.

Performing some basic load test using a remote client, it turned out that for a larger number of HTTP requests in a short time, this setting can improve your Domino HTTP server performance.

This also reduces the number of TCP/IP sessions opened.

Most of my servers did already use the following values -- The default setting would be 5 requests, which is a bit too low.

HTTP persistent connection:
Maximum requests per persistent connection:

Description: Specify the maximum number of HTTP requests that can be handled on one persistent connection. The default is 5.


Simple Test Setup

I had a very simple setup for my quick test. The tool ran the following load:

Threads 10
Requests per thread 1000
Total Transfer 56 MB
Data/Req 5887 bytes

Which resulted in the following performance values:

Test  Average request time (ms)  Total run-time (sec)
5 requests per connection
10 requests per connection
100 requests per connection
TLS connection

TLS Sessions

One important side note is that TLS/SSL sessions work differently. A TLS/SSL session has way higher overhead than establishing a new TCP/IP session.

Therefore the TLS/SLL stack uses TLS session resumption and tries to reuse sessions as much as it can.

You can see the TLS performance with a ECDSA NIST P-256 key in the table as reference.

Log output from SSL_LOG_SUCCESS=1

TLS1.2 resumed (52459) -> (443) - ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 (0xC02C)


You should really double check, if your Domino HTTP server has persistent connections enabled and in most cases you should really increase value of the request at least to 40.



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