Display more informative error message in authentication process.

When backends offers mistakenly different authentication methods,
pgpool just showed:

          "unable to read message length"
          "message length (%d) in slot %d does not match with slot 0(%d)", length, i, length0)));

because pool_read_message_length() called ereport(ERROR) in this
case. Actually the caller pool_do_auth() prepared more informative
message:

        ereport(ERROR,
                        (errmsg("invalid authentication packet from backend"),
                         errdetail("failed to get the authentication packet length"),
                         errhint("This is likely caused by the inconsistency of auth method among DB nodes. \
                                                Please check the previous error messages (hint: length field) \
                                                from pool_read_message_length and recheck the pg_hba.conf settings.")));

Change ereport(ERROR) to ereport(LOG) in pool_read_message_length() so
that the informative message actually shows up.

diff --git a/src/auth/pool_auth.c b/src/auth/pool_auth.c
index cb37c0aeaaae2e9de55d8755be037ea6f466a43e..7042bb14d4a9c8208eb2306a4ccfbc88dd30b497 100644 (file)
--- a/src/auth/pool_auth.c
+++ b/src/auth/pool_auth.c
@@ -1130,10 +1130,12 @@ int pool_read_message_length(POOL_CONNECTION_POOL *cp)
                                 errdetail("slot: %d length: %d", i, length)));
 
                if (length != length0)
-            ereport(ERROR,
-                    (errmsg("unable to read message length"),
-                     errdetail("message length (%d) in slot %d does not match with slot 0(%d)", length, i, length0)));
-            
+               {
+                       ereport(LOG,
+                                       (errmsg("unable to read message length"),
+                                        errdetail("message length (%d) in slot %d does not match with slot 0(%d)", length, i, length0)));
+                       return -1;
+               }
        }
 
        if (length0 < 0)