maria-developers team mailing list archive

[Michael Widenius <monty@xxxxxxxxxxxx>]

Hi!

>>>>> "md" == md  <md@xxxxxxxxxxxxx> writes:

md> Monty:
md> I received your email and am re-posting to the maria developers list.

md> It is truly amazing that maria developers are HAPPY with replication as 
md> it stands right now.
md> binary logs, Single SLAVE reading from individual masters, bla-bla-bla.....

We are constantly working on making replication better. However with
few resources it does take some time.

- MariaDB 5.5 added group commit, which did speed up replication 3-5x
  for many common cases.
- MariaDB 10.0 support already multiple slaves.
- We are working on two different patches for parallel replication
  (one with taobao, on our own) that.

The binary log is actually not a bad idea as it makes it easy to shift
binary logs around and also support multiple storage engines.

md> All the current replication code is like walking on the edge of a cliff, 
md> anything goes wrong
md> and the replication process STOPS with an error.  And a HUMAN BEING must 
md> wake up from their
md> blissful sleep to get the process started again and figure out what 
md> happened.

There are some improvement coming for that in MySQL 5.6 and MariaDB 10.0

md> And I just LOVE having to:

md> LOCK TABLES;
md> RESET MASTER
md> SET SLAVE OFF;
md> MYSQLDUMP;
md> COPY FILES TO SLAVE;
md> SET MASTER TO 'sql_log_bin=45678945";
md> SET SLAVE ON;
md> SECONDS BEHIND MASTER...
md> WRITE A THESIS FOR MY PHD IN ROCKET SCIENCE
md> Oh my GOD!!!!!!

This will be fixed in MySQL 5.6 and MariaDB 10.1

md> What an absolute nightmare of a design, it works, just not well.

md> I have not made an in depth study of galera, but I refuse to make 
md> replication another research project,
md> replication should be EASY, auto-healing, self analyzing, N-MASTER and 
md> with simple source code.

Yes, it should. However to do that is a LOT of work and can't just be
done over night.

md> I will open source the files that I use to change the MYSQLD daemon.

md> The best way to debug MariaDB on Linux is to run the program in Netbeans 
md> 7.1.2.
md> You can even give it command line parameters to work against
md> a currently installed system with the data/conf files in place.

That is how I work daily on Linux; It's trivial to setup in any
development environment.
(Just one simple .my.cnf file in your home directory with the right
paths and things works)

md> Your trace idea is very nice, but there is nothing like STEPPING THROUGH 
md> the code
md> in NetBeans/GDB in a nice IDE instead of cryptic command line GDB.

I am using ddd for debugging code.

However for understanding code flows and finding bugs that involve wrong
data, the trace file is MUCH better than any debugger.

Regards,
Monty