Hello, imagine the following configuration:
frontend F1 use_backend BACKUP_B1 if B1_IS_FULL default_backend B1 backend B1 server s_i ... server s_j backend BACKUP_B1 server b_i ... server b_j --------- frontend F2 use_backend BACKUP_B2 if B2_IS_FULL default_backend B2 backend B2 server s_k ... server s_m backend BACKUP_B2 server b_k ... server b_m ---------- <...> So basically I have a number of backends B1 ... Bn which use different subsets of the same server pool s_1 ... s_N. Each backend have "BACKUP_" backend pair, which should be used only when each server in primary backend has more than a defined number of active sessions (each server may have active sessions via different backends: B1, B2, ..., Bn). What is the easiest way to define Bn_IS_FULL acl? So far I came with the following solution: in each frontend Fn section write: tcp-request content set-var(sess.s_1_conn) srv_conn(B1/s_1) tcp-request content set-var(sess.s_1_conn) srv_conn(B2/s_1),add(sess.s_1_conn) # <...> repeat last line for each backend which has s_1. We will have total number of active connections to s_1 # Repeat the above block for each server s_2, ..., s_N #Then define acl, assume the max number of active sessions is 7: acl F1_IS_FULL var(sess.s_1_conn) ge 7 var(sess.s_2_conn) ge 7 <...> but it looks ugly, we need to replicate the same logic in each frontend and use a lot of code to count sessions. There should probably be a simpler way to track down the total number of active sessions for a server which participates in several backends. Thanks in advance.
