Jonathan's questions

I am tasked with trying to find a way to download zipped logs from a remote server. There are quite a bit of these logs and they are constantly created.

I do have limited ssh access to the remote server and can scp or rsync the files.

However, due to the sheer size of these logs file, I do not want to rsync all of them. The logs could get to terabytes and for rsync to compare them may take some time. I only want to get any new file that was created/last updated an hour ago.

I also am worried that I will rsync logs that are in the process of being created, so I was thinking to only rsync files that were last modified 3-5 minutes ago.

Would anyone be so kind as to help me with such a process? Thank you in advance.

I am interested in using HA proxy as a failover/load balancer in our MySQL environment. We have a master-master + 2 slaves setup.

I would like for the master/master setup, even though they are setup for it, to only write to one master. This is to avoid issues with split-brain.

I do plan on having a separate port on HA proxy for reads and for that to be load balanaced.

Is it possible use HA proxy as a fail over only and if so, how would you set it?

Is it something like balance with roundrobin, but give one of the servers a weight of 1 and the other a weight of 0? With the idea being if the first server goes offline, the second will be used no matter its weight?

I am having quite a few problems on a tricky server.

One of my main problems at the moment is that tcpdump cannot seem to get the packets sent to mysql, unless I tinker with MySQL a bit.

This is what I run:

tcpdump -s 65535 -x -nn -q -tttt -i any -c 99999 port 3306

When I run this, no output is shown.

If however, I log into mysql using

mysql -h 127.0.0.1

..then tcpdump does show some output.

My problem is that the current traffic coming from apache does not show up using tcpdump and I do not know if I need to change a parameter in tcpdump, MySQL or apache.

Some more info:

netstat -tap | grep mysql

tcp        0      0 *:mysql   *:*                         LISTEN      2238/mysqld

cat /etc/hosts

127.0.0.1               localhost localhost.localdomain

Can anyone please help?

Is it possible to run triggers on a MySQL read-only slave?

Meaning, the Master receives all the insert/update statements. Then passes them to the slave via binary log. On the slave, is it possible to have triggers installed that will react to the binary logs, so that I could enable some reporting/BI capabilities?