Questions[percona](server)

Basically what I'm looking for is a way to tell mysql (percona-flavored) to take the following steps:

• Flush all committed transactions to the filesystem
• Start buffering all transactions (keep the filesystem in a coherent state)
• Wait for me to do something (take a zfs snapshot)
• Unbuffer writes and resume normal operations

A solution which allows DDL statements to break the backup are acceptable (because this backup solution will be applied frequently and DDL statements will be very infrequent - worst-case scenario would be having to roll back a db one hour more than expected).

Backup operations should be minimally disruptive to performance, but this is not a system under heavy load. Solutions which perform this procedure per-database or system-wide are both fine, though the latter is somewhat preferred.

I'm trying to use the Percona Apache Monitoring [Cacti] Template for Memcached.

They do indeed warn that you can't use the openbsd version of the package and provide a solution for Ubuntu/Debian users, i.e.:

You need nc on the server. Some versions of nc accept different command-line options. You can change the options used by configuring the PHP script. If you don’t want to do this for some reason, then you can install a version of nc that conforms to the expectations coded in the script’s default configuration instead. On Debian/Ubuntu, netcat-openbsd does not work, so you need the netcat-traditional package, and you need to switch to /bin/nc.traditional...

Since the RHEL 6.x version indeed comes from openbsd (confirmed by rpm -qi nc) how does one go about getting this installed on RHEL/CentOS?

Anyone else running these Percona templates on RHEL/CentOS? What did you do? alien the Debian package?

Update 1: FWIW, I tried to use GNU netcat by compiling it from source but it doesn't seem to have the exact options required by the Cacti template either (i.e. there is no analogy for -C or -q1 so it seems)

Update 2: I alien[ed] the netcat-traditional_1.10-38_amd64.deb package to make a .tgz and it does produce a binary "nc.traditional" and that version has the -q option but no -C

Update 3: I alied[ed] netcat-openbsd_1.89-3ubuntu2_amd64.deb as suggested by cjc and although it provides the -C and -q options it does not appear to work with the template. I also removed the -q1 option from the nc_cmd as suggested by quanta. Still doesn't graph or produce output from the commandline.

Update 4: I built the source RPM as suggested by dmourati and left out the -q1 as suggested by quanta and still it doesn't graph or produce output from the commandline. Maybe the source RPM solution and/or not passing -q1 works on RHEL 5.x, I dunno. At this point I admit defeat.

Cheers

I'm running Mysql in production today but are planning to switch to either MariaDB or Percona server when I move to new servers. The main reason for the switch is to distance us from Oracle, but also to get better performance and new features.

It looks like Percona server and MariaDB is pretty similar, and they also promote each other's solutions. What would you say is the main difference between them?

I have seen Cron sync mysql tables . But I cannot use replication. I used to use percona-toolkit and it worked perfectly. I could run the sync command on demand or just run it via cron. It would compare checksums on the two tables and do inserts, updates, deletes etc. However Perl(DBD::mysql) and MySQL have some incompatibilities in a new server I'm going to run this on and I cannot use pt-table-sync. Is there a similar solution which uses something other than Perl/DBD?

Edit : (more details, clarity)

1. Both the source and target tables are live tables and in constant use. Hence a solution with the table not existing (eg. a DROP TABLE is done) would not be acceptable.
2. Cannot use replication or any such modifications to the server itself. The solution has to work on the client side.
3. In this particular scenario both the tables are in the same server, but different DBs (eg. db1.tbl db2.tbl). However, a solution which does not rely on this fact would definitely be a bonus
4. Network latency is unlikely to be an issue. In this case the script runs on a server in the same datacenter.
5. Cannot use Perl (incompatibility between Perl and MySQL - 64 bit vs 32 bit)

I am preparing for setting up a MySQL master-slave or master-master relationship. Right now I have a single MySQL production server, and of course I don't want a lot of downtime while I connect the slave.

Is there no way I can make connect an empty slave and let it "slowly" synchronize data from the master, until they are identical?

I have noticed that I can take a transactional dump with mysqldump on the master and then import that into the slave, but by the time the slave has imported the dump, a lot of new rows will have been written and how will the slave get these?

I hope I am missing something obvious here, but extensive googling gives such advice such as "since this will result in less downtime in the future, some downtime now maybe isn't such a bad thing". But I would really like to avoid that.

Related question for MyISAM, but I use InnoDB.