tcp settings

[Rob Sargent <robjsargent@xxxxxxxxx>]

    I'm wondering if
      there's a disconnect between my servers postgresql.conf and the
      system tcp settings? Are the config names supposed to match a file
      in /proc/sys/net/ipv4?
      
      
      In postgres 14 install's postgresql.conf on centos 7:
      
    
> # - TCP
>         settings -
>       # see "man tcp" for
>         details
>       
>       #tcp_keepalives_idle
>         = 0                # TCP_KEEPIDLE, in seconds;
>                                              
>         # 0 selects the system default
>       #tcp_keepalives_interval
>         = 0            # TCP_KEEPINTVL, in seconds;
>                                              
>         # 0 selects the system default
>       #tcp_keepalives_count
>         = 0               # TCP_KEEPCNT;
>                                              
>         # 0 selects the system default
>       #tcp_user_timeout =
>         0                   # TCP_USER_TIMEOUT, in milliseconds;
>                                              
>         # 0 selects the system default
>       
>       #client_connection_check_interval
>         = 0   # time between checks for client
>                                              
>         # disconnection while running queries;
>                                              
>         # 0 for never
>     
    and in the
      /proc/sys/net/ipv4 I see no "keepalives" plural.
    
> tcp_abort_on_overflow            
>         tcp_fastopen_key           tcp_min_snd_mss          
>         tcp_slow_start_after_idle    
>         tcp_adv_win_scale                 tcp_fin_timeout           
>         tcp_min_tso_segs          tcp_stdurg                   
>         tcp_allowed_congestion_control    tcp_frto                  
>         tcp_moderate_rcvbuf       tcp_synack_retries                 
>         tcp_app_win                       tcp_invalid_ratelimit     
>         tcp_mtu_probing           tcp_syncookies                     
>         tcp_autocorking                   tcp_keepalive_intvl(75)   
>         tcp_no_metrics_save       tcp_syn_retries                    
>         tcp_available_congestion_control  tcp_keepalive_probes(9)   
>         tcp_notsent_lowat         tcp_thin_dupack                    
>         tcp_base_mss                      tcp_keepalive_time(7200)  
>         tcp_orphan_retries        tcp_thin_linear_timeouts           
>         tcp_challenge_ack_limit           tcp_limit_output_bytes    
>         tcp_reordering            tcp_timestamps                     
>         tcp_congestion_control            tcp_low_latency           
>         tcp_retrans_collapse      tcp_tso_win_divisor           
>         tcp_dsack                         tcp_max_orphans           
>         tcp_retries1              tcp_tw_recycle                      
>         tcp_early_retrans                 tcp_max_ssthresh          
>         tcp_retries2              tcp_tw_reuse                  
>         tcp_ecn                           tcp_max_syn_backlog       
>         tcp_rfc1337               tcp_window_scaling            
>         tcp_fack                          tcp_max_tw_buckets        
>         tcp_rmem                  tcp_wmem              
>         tcp_fastopen                      tcp_mem                   
>         tcp_sack                  tcp_workaround_signed_windows
>       
>       
>     
    My issue is that psql is timing out with "SSL SYSCALL error:
    Connection timed out".  The TCP defaults for keepalive look fine to
    me but not what I'm experiencing.  I have PGCONNECT_TIMEOUT=0 in my
    env for psql.