Remote poller and script server

[adankert]

I have a Cacti installation with 3 pollers.
One main.
One remote poller on same site as main.
One remote poller on different continet, latency is 120-140ms.

The main poller and local remote poller works fine.
The remote poller on different continet does not work.
It looks like the php script servers get stuck: They never receive any input on stdin.

When using 'strace' I can see that they are waiting for input:
# strace -p 18531
strace: Process 18531 attached
read(0,

The poll cycle times out but script servers live on for a few minutes before dying. Typical situation, 4 minutes of pollers living:
[root@btr-srv-cnt-01 ~]# ps -ef | grep php
cactius+ 18331 18329 0 06:18 ? 00:00:00 /bin/sh -c php /var/www/html/cacti/poller.php --debug > /tmp/poller.log 2>&1
cactius+ 18332 18331 0 06:18 ? 00:00:00 php /var/www/html/cacti/poller.php --debug
cactius+ 18392 18390 0 06:19 ? 00:00:00 /bin/sh -c php /var/www/html/cacti/poller.php --debug > /tmp/poller.log 2>&1
cactius+ 18393 18392 0 06:19 ? 00:00:00 php /var/www/html/cacti/poller.php --debug
cactius+ 18456 18453 0 06:20 ? 00:00:00 /bin/sh -c php /var/www/html/cacti/poller.php --debug > /tmp/poller.log 2>&1
cactius+ 18458 18456 0 06:20 ? 00:00:00 php /var/www/html/cacti/poller.php --debug
cactius+ 18487 18481 0 06:20 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18488 18485 0 06:20 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18492 18481 0 06:20 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18494 18485 0 06:20 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18497 18481 0 06:20 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18499 18485 0 06:20 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18508 18481 0 06:20 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18531 18485 0 06:20 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18544 18481 0 06:20 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18548 18485 0 06:20 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18551 18549 0 06:21 ? 00:00:00 /bin/sh -c php /var/www/html/cacti/poller.php --debug > /tmp/poller.log 2>&1
cactius+ 18552 18551 1 06:21 ? 00:00:00 php /var/www/html/cacti/poller.php --debug
cactius+ 18562 18481 0 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18565 18485 0 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18573 18481 0 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18577 18485 0 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18578 18572 0 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18579 18576 1 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18580 18481 1 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18581 18485 1 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18583 18572 1 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18584 18576 2 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4
cactius+ 18586 18481 4 06:21 ? 00:00:00 /bin/php -q /var/www/html/cacti-1.1.25/script_server.php spine 4

The "local" remote poller and the remote poller over wan are configured exactly the same. The only difference is main + local remote runs RHEL 7. Wan remote poller runs Centos 7.
All database connections and grants are OK!

Any hints/tips/suggestions are very welcome.

[phalek]

Can you check if the pollers are all the same, especially the script/resources path content ?

[adankert]

Thanks for getting back to me on this.
cacti/scripts and cacti/resources are in sync. Same files, owner and sizes.

[adankert]

To follow up on my own post.

The startup of a remote poller over wan connection with ~140ms latency is very slow.
Database chit chat etc takes ~15seconds before Cacti console displays poller as "Running".
Remote poller on same LAN is almost instant.

[ikorzha758]

As per Cigamit, Cacti 1.2 is promised to be more semi-autonomous. Until then there is nothing you can do with remote pollers with high latency.
I have a similar issue. My remote pollers are 60ms and 80ms away.