Hello Yugo-san,
TState has a field called "conn_duration" and this is, the comment says,
"cumulated connection and deconnection delays". This value is summed over
threads and reported as "average connection time" under -C/--connect.
If this options is not specified, the value is never used.
Yep.
However, I found that conn_duration is calculated even when -C/--connect
is not specified, which is waste. SO we can remove this code as fixed in
the attached patch.
I'm fine with the implied code simplification, but it deserves a comment.
In addition, deconnection delays are not cumulated even under -C/--connect
in spite of mentioned in the comment. I also fixed this in the attached patch.
I'm fine with that, even if it only concerns is_connect. I've updated the
command to work whether now is initially set or not. I'm unsure whether
closing a pg connection actually waits for anything, so probably the
impact is rather small anyway. It cannot be usefully measured when
!is_connect, because thread do that when then feel like it, whereas on
connection we can use barriers to have something which makes sense.
Also, there is the issue of connection failures: the attached version adds
an error message and exit for initial connections consistently.
This is not done with is_connect, though, and I'm unsure what we should
really do.
--
Fabien.
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index d7479925cb..9d2abbfb68 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -3171,6 +3171,7 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
if ((st->con = doConnect()) == NULL)
{
+ /* as the bench is already running, we do not abort */
pg_log_error("client %d aborted while establishing connection", st->id);
st->state = CSTATE_ABORTED;
break;
@@ -3536,8 +3537,12 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
if (is_connect)
{
+ pg_time_usec_t start = now;
+
+ pg_time_now_lazy(&start);
finishCon(st);
- now = 0;
+ now = pg_time_now();
+ thread->conn_duration += now - start;
}
if ((st->cnt >= nxacts && duration <= 0) || timer_exceeded)
@@ -3561,6 +3566,7 @@ advanceConnectionState(TState *thread, CState *st, StatsData *agg)
*/
case CSTATE_ABORTED:
case CSTATE_FINISHED:
+ /* per-thread last disconnection time is not measured */
finishCon(st);
return;
}
@@ -4405,7 +4411,10 @@ runInitSteps(const char *initialize_steps)
initPQExpBuffer(&stats);
if ((con = doConnect()) == NULL)
+ {
+ pg_log_fatal("connection for initialization failed");
exit(1);
+ }
setup_cancel_handler(NULL);
SetCancelConn(con);
@@ -6332,7 +6341,10 @@ main(int argc, char **argv)
/* opening connection... */
con = doConnect();
if (con == NULL)
+ {
+ pg_log_fatal("setup connection failed");
exit(1);
+ }
pg_log_debug("pghost: %s pgport: %s nclients: %d %s: %d dbName: %s",
PQhost(con), PQport(con), nclients,
@@ -6548,7 +6560,7 @@ threadRun(void *arg)
if (thread->logfile == NULL)
{
pg_log_fatal("could not open logfile \"%s\": %m", logpath);
- goto done;
+ exit(1);
}
}
@@ -6561,6 +6573,7 @@ threadRun(void *arg)
thread_start = pg_time_now();
thread->started_time = thread_start;
+ thread->conn_duration = 0;
last_report = thread_start;
next_report = last_report + (int64) 1000000 * progress;
@@ -6572,26 +6585,13 @@ threadRun(void *arg)
{
if ((state[i].con = doConnect()) == NULL)
{
- /*
- * On connection failure, we meet the barrier here in place of
- * GO before proceeding to the "done" path which will cleanup,
- * so as to avoid locking the process.
- *
- * It is unclear whether it is worth doing anything rather
- * than coldly exiting with an error message.
- */
- THREAD_BARRIER_WAIT(&barrier);
- goto done;
+ /* coldly abort on connection failure */
+ pg_log_fatal("cannot create connection for thread %d client %d",
+ thread->tid, i);
+ exit(1);
}
}
-
- /* compute connection delay */
- thread->conn_duration = pg_time_now() - thread->started_time;
- }
- else
- {
- /* no connection delay to record */
- thread->conn_duration = 0;
+ /* connection delay is measured globally between the barriers */
}
/* GO */
