i just moved out RDS and setup my own Master/Slave mysql replication.
The replication is working fine, but my slave node is accepting changes, differently of what happened on RDS (the server generated an error saying that the server was on read only mode).
I trie to activate on my my.cnf the configuration read_only = ON (on the slave)...
but even after a service restart, the server continues to accept changes.
What am i doing wrong? I want that the servers accepts changes ONLY from the replication connection...
Just found it...I was using root user, and root can do anything.... for user without super privileges, the read-only IS working.
Related
I am having a difficult time in setting Master-Slave configuration.
Master Database runs on Ubuntu( Amazon AWS instance) and successfully set-up master replication.
I have localhost as a Slave Server. (Windows Machine).
Snapshot of Master Database
Master database has record
Binar Log Information
Process List on Master Replication
Status of Master Replication
I debug master replication which works okay I guess.
On the Salve Side:
Status on Slave Side
Even though MASTER_LOG and MASTER_POS are synced but data doesn't.
Currently, I have 0 table on Slave side and 34 tables on Master side.
Tables on Slave side
I am open to any suggestion or any reference do you have.
I spend an entire day and trying to find what I did wrong.
I want to Sync my Local database with a database hosted on remote-server.
Update: Thigs I did to debug the Master-Slave Replication
Checked Master Database is up and running.
Master Status and Connected Slaves. [Which includes unique id for
each server.]
Slave database is up and running [Including Slave IO Thread and
SQL thread is running.]
These three steps ensure that Master-Slave replication is up and running without any problem.
Handling Data Sync Problem
Created/update/delete data in the master database to check
whether data is sync on a server or not.
Checked Binary Log [Specifically I checked the file size. If I
entered data file size will continuously increasing.]
Thanks in advance.
we had similar problem - read more about gotchas in "binlog-do-db" and "replication-do-db" and related parameters. Here is a big problem with crossdatabase references. At the and we had to remove these settings limiting replication.
Why MySQL’s binlog-do-db option is dangerous
Gotchas in MySQL replication
As your show slave status output says you enabled Replicate_DO_DB for the DB "Arihantpos" at the same time you did Binglog_Do_Db for the same db
try to remove Binglog_Do_Db from config file and restart mysql and start replication again
I put the percona toolkit onto my DB hosts so I could try and deal with a problem with mysql going silently out of sync. That is replication seems fine on all nodes. Slave IO running / Slave SQL running and 0 seconds behind master.
I have 4 dbs setup in master/master on the first two, and two slaves, I'm using MariaDB-server-10.0.21 for the MySQL database on each node.
Yet the content of the wiki I run on them seems to go out of sync even with those positive indicators. For instance, you'll create a page, save it, get the thumbs up from the wiki. Then reload the page and the content will be gone! Then you point the wiki config to look at each db one at a time, reload the page. Until you find the db that saved the changes you made.
Then dump that db, stop the slaves on each host one at time and then import that version of the database. It's a real pain!
So I installed the percona toolkit after reading an article on how to solve this problem.
And when I run the pt-table-checksum command I get this error, saying Replication filters are set on these hosts:
[root#db1:~] #pt-table-checksum --replicate=test.checksum --databases=sean --ignore-tables=semaphore localhost
10-17T00:31:11 Replication filters are set on these hosts:
db3
binlog_do_db = jfwiki,jokefire,bacula,mysql
db2
binlog_do_db = jfwiki,jokefire,bacula,mysql
db4
binlog_do_db = jfwiki,jokefire,bacula,mysql
Please read the --check-replication-filters documentation to learn how to solve this problem. at /bin/pt-table-checksum line 9644.
But that EC2 host it claims that it's having trouble contacting equates to my 4th database host. I found out by ssh'ing in as my user to that DNS address. And I have no trouble at all logging into that host on the command line using mysql:
Can someone please explain what does this error mean, and how can I fix the issue? Is there any general advice you can give for mysql replication falling silently out of sync?
Thanks
Some of the pt tools need to create their own database and have it replicated. Your binlog_do_db prevents the extra db from being replicated, hence preventing that tool from working.
While you have the binlog_do removed, see what db it being built. Then add it.
I'm using mysql 5.22 version for master and slave replication. when I execute the show slave status command it's showing slave_io_state as connecting. how to solve this problem.
Please help me the same.
Regards,
Yasar
From here-
run a "show master status" on the master DB. It will give you the
correct values to update your slave with. From your slave status, it
looks like your slave has successfully connected to the master and is
awaiting log events. To me, this means your slave user has been
properly set up, and has the correct access. It really seems like you
just need to sync the correct log file position. Careful, because to
get a good sync, you should probably stop the master, dump the DB,
record the master log file positions, then start the master,import the
DB on the slave, and finally start the slave in slave mode using the
correct master log file pos. I've done this about 30 times, and if you
don't follow those steps almost exactly, you will get a bad sync.
Else go through this(How to set up replication) again, to see if there are some config problem.
If Slave I/O thread is showing Connecting to Master status check these things:
Verify the privileges for the user being used for replication on the
master.
Check that the host name of the master is correct and that you are using the correct port to connect to the master. The port used for replication is the same as used for client network communication (the default is 3306). For the host name, ensure that the name resolves to the correct IP address.
Check that networking has not been disabled on the master or slave. Look for the skip-networking option in the configuration file. If present, comment it out or remove it.
If the master has a firewall or IP filtering configuration, ensure that the network port being used for MySQL is not being filtered.
Check that you can reach the master by using ping or traceroute/tracert to reach the host.
I have an existing mysql replication set up (Windows 2008 to Ubuntu 9.04) and created several new tables in the master database. These are not showing up in the slave database.
Do new tables automatically get copied to the slave DB, or do I need to set up replication again?
Thanks!
I'm going to assume that other data is successfully replicating.
Replication in mysql is per-server, so the most likely problems are that either you aren't binloging the events, or that the slave is ignoring them.
For binglogs, verify you aren't turning sql_log_bin off for the connection (which would require SUPER) and that the various options binary-log options are set correctly. You can verify this by running mysqlbinlog on the server's binlogs.
On the slave side, check the replication options.
I have multiple mysql databases and I want to perform some administration tasks on a particular database. How do I ensure that no one else can connect to that database while the tasks in progress?
Apparently, you can use the FLUSH command for this as such:
> FLUSH TABLES WITH READ LOCK;
and then
> UNLOCK TABLES;
to unlock the database again. Unsure if some setting needs to be set on the tables to allow a readlock. You can test this by trying to do a manual insert after the database is locked and if you get an error message about the table being locked, you know it worked.
More information on FLUSH command
You have a couple of options, as I see it:
Shutdown mysqld, the daemon that connections to be established to databases. This has the downside of preventing access to all the mysql databases on that computer.
Move the file or change the access permissions to it, so that only your user may work with it. (I have no idea if this will work.) The database files are located somewhere like /var/lib/mysql. Just don't forget when you're done to change them back to something that mysqld will be able to work with!
Good luck!
If you can afford stopping the server for the time of maintenance, stop the daemon and reconfigure it to not listen to network connections. Only allow connections through a local UNIX socket.
Then logon locally on the same machine, either physically or via SSH. As long as nobody else has access to the machine, this will ensure you are alone. When done, restore the original configuration file and restart the daemon.
A different approach would be to temporarily disable all user accounts but "root" (or whatever you use to do your maintenance) for the particular database. This has the drawback however of actually messing with account data which is a little more risky than just preventing network connections.