linux - Can not connect right now. can not assign requested address? - Server Fault


we experiencing high load on our dedicated servers lately. users see error message

"can not connect right now. can not assign requested address"

popping randomly.

we have 2 linux application servers, running lightspeed web server , 1 mysql/mariadb database server.

we not sure, if error coming web server or mysql.

is there can change in our config, stop error coming up?

i think need more information in order (what kind of server, cpu, memory etc). here basic items check:

  1. run top see processes taking highest memory , cpu. can run free -m see memory usage.
  2. based on above output check lsof|grep <app_name> see files open. tell application focus on.
  3. netstat -vatnl |grep time_wait or netstat -tulpen |grep <port>. check tcp connections , status. "cannot assign" message seems related networking binding or tcp sockets. should check tcp settings such net.core.somaxconn or net.ipv4.tcp_max_syn_backlog. there tons of guides out there tune these values web , database servers.
  4. for mysql load , performance, can run show processlist mysql prompt. provide list of current queries. example, here can identify query has long runtime.

hope helps. luck!


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