`socket_keepalive` doesn't work with shaded clickhouse-jdbc

[ostinru]

socket_keepalive doesnt' applied

Steps to reproduce

Note: I would expect that instruction from official site[1] should end up with the same result.

1. Specify following option for apache/cloudberry-pxf:

     <property>
      <name>jdbc.connection.property.socket_keepalive</name>
      <value>true</value>
     </property>
   

   or in JDBC URL &socket_keepalive=true
2. expect that SO_KEEPALIVE=true. However it is not.
   Actual:

   # ss -Otnpio state established | grep -F '8123'
   0      0                    [::ffff:10.1.0.9]:44198               [::ffff:10.1.0.20]:8123  users:(("java",pid=2731285,fd=34)) ts sack illinois wscale:10,4 rto:201 rtt:0.343/0.188 <cut>
   

   Expected (spot the timer section!):

   0      0                  [::ffff:10.1.0.29]:15938                 [::ffff:10.1.0.20]:8123  users:(("java",pid=514753,fd=36)) timer:(keepalive,10sec,0) ts sack illinois wscale:10,4 rto:201 rtt:0.249/0.123 <cut>
   

Environment

• Cloud
• Client version: 0.9.8 and 0.10.0
• OS: Ubuntu 22.04

ClickHouse Server

• ClickHouse Server version: 26.7.5.10
• CREATE TABLE statements for tables involved:

  SELECT toInt32(sleep(600)) AS slept
  SETTINGS
     function_sleep_max_microseconds_per_block = 600000000,
     max_execution_time = 0
  

[1] https://clickhouse.com/docs/integrations/language-clients/java/jdbc#linux

[ostinru]

Surprisingly, driver built from source sets keepalive by default, maven version - don't. It is because my build pulls fresh httpcore5, where default behaviour changed [2].

ClickHouse team, what is expected behaviour? I would expect to always have keepalive=true without option to disable it.

[2] apache/httpcomponents-core#550

[ostinru]

It seems, that #3079 changes:
httpclient5 5.4.4 -> 5.6.4
httpcore5 5.3.4 -> 5.4.3
tcp_keepalive OFF -> ON (idle=5s, interval=5s, count=3)

However I am not 100% sure about transitive dependencies and shaded libraries. Anyway, documentation should be updated to make it clear, how to enable tcp_keepalive.

[chernser]

Good day, @ostinru !

Thank you for the analysis! We will look into it shortly.
Would you please tell more about your usage of tcp_keepalive? We gathering this information to adopt client and document the experience.

Thanks!