We have a large MySQL table of sales that we would like to replicate over to Redshift, streaming data using AWS Database Migration Service (DMS). This table is insert only. Once a sale is added it is never deleted or modified.
We would like to prune sales after a TTL regularly (they would then be in Redshift) to keep the table small. However deleting records would be replicated over to Redshift.
It is possible for DMS to either discard DELETEs or otherwise prevent the records from being deleted from the Redshift target?
We cannot do this from the AWS DMS. However, you should be looking at the MYSQL replication properties to see if there a way you can tell mysql not to replicate deletes from the Binary Logs?
I know this can be done when source is SQL Server where we can tell sql server replication to not propagate deletes (as attached).
Screenshot from SQL Server Replication Properties for DMS
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I am currently prepping to upgrade from MySQL 5.7 to MySQL 8.
I am using RDS on AWS with a master server and read replicas. The read replicas use MySQL replication but are read-only copies.
One of the issues I need to resolve prior to upgrade is that I have some tables on production databases with COMPACT row format which need updating to DYNAMIC.
I know I can do this with the following and have a script which will find and update all tables needed.
ALTER TABLE `tablename` ROW_FORMAT=DYNAMIC;
There are a large number of potentially large tables (millions of rows) that need updating.
What does this change actually do in the background? Is it safe to run this on a production server whilst it is in use? Does it lock the tables whilst it makes the change?
I have run a test on a restored copy of the server. This takes a while as I'd expect, and as such it's hard for me to test to be sure everything is working fine during this whole process. It does complete successfully eventually though
I have a RDS Mysql database instance on AWS with 1000 tables (lets call it root instance).
I need to create another instance of this database with only the rows that match some foreign key id. This new instance must be in mirror with the root instance so I can query the new values as soon as they get inserted. Question: Is there any way to achieve this with AWS tools? Or do I need to code id?
As far as I know, I can create instances in a cluster to be mirrored with the root instance, but these instances are a full copy and I need only some rows.
Neither AWS nor MySQL provide a solution for what you describe.
You would have to develop your own solution. For example a CDC (change data capture) client (Debezium is a popular open-source CDC implementation) to parse the binary logs of your RDS instance, filter for the rows you want, and insert them to the other instance.
This isn't possible with RDS.
You can "fake it" by converting the tables you don't want replicated to Engine=Blackhole, however you have to edit your parameter-group and set "read-only" to 0, instead of the default "{TrueIfReplica}".
and to handle your case you can create a view that pulls only these records
Alternately, you would need to run your own slave server on EC2 with the RDS server as the master (this is possible if you're running MySQL 5.6 on RDS, but not 5.5 or below), however it's extremely complicated to set up.
is there a way to replicate mysql while the master server already has a lot of data.I tried the normal way, but I had difficulty getting the MASTER_LOG_POS value. how can the slave server be able to replicate data that previously existed on the master server.
Generally you start with an exact full copy of your existing database. This means creating a real copy of your MySQL data directory (while the server is off), go with a (consistent) snapshot, or use a tool like Percona XtraBackup.
Only after you have 2 identical MySQL servers, you can start replicating. Note that using a tool like mysqldump is not a good idea for consistent snapshots.
If you have a relatively small amount of data you could use mysqldump --master-data=1 --single-transaction. This will create a snapshot with the correct master-binlog and position required. This should not be used for production environments or large amounts of data.
I am trying to configure MySQL databases using the Master-Slave replication. Before I realized that I had to set up my environment using this replication, I already have 2 separate servers running their own MySQL DB. Each of these servers are configured the exact same. The MySQL DB are configured with hundreds of tables.
Is there a way that i can set up (Master-Slave) Replication using the configured DB's? Or will i have to start from scratch and configure the replication first and then load in all the DB tables?
You can delete all data from one of the servers. Remaining one with the data will be your Master. Then use mysqldump to backup all the data and insert it to the slave.
Take a look for the detailed instructions on the page below:
https://livecaller.io/blog/how-to-set-up-mysql-master-slave-replication/
If the data is exactly same in both the MySQL database then you can start master slave replication, but you need to be sure that the data is same. MySQL will not check that, and if there is some discrepancy in the primary key then it will throw error immediately after next DML statement.
To be on a safer side, drop the database from one server, and restore it using the MySQL dump of another server. This will give the surety that database is same on both the server.
Take the reference from the below link to establish replication between two MySQL servers.
https://www.digitalocean.com/community/tutorials/how-to-set-up-master-slave-replication-in-mysql
I'm working on a project that has a MySQL transactional database backing up a web application. The company uses SQL Server for back office and reporting applications. What is the best way to update SQL Server with the data from MySQL? Right now, we are performing a dump of the MySQL data and doing a full restore. This may not be feasible much longer due to the increasing size of the database.
I would prefer a solution that copies only newly inserted and updated rows. I also need the SQL Server database to be static after the updates are applied. Basically, it should change once a day. I can update SQL Server from a local copy of MySQL (i.e. not production) Is there a way to apply MySQL replication to a slave server at specified intervals? A perfect solution is to run a once daily update on MySQL that syncs the database as of a point in time.
Can you find a way to snapshot the mySQL DB and then do the copy? It would make an instant logical copy of the database which would be frozen in time.
http://aspiringsysadmin.com/blog/2007/08/13/consistent-mysql-backups-using-zfs-snapshots/
ZFS filesystem can do this - but you haven't mentioned your hardware/OS.
Also, perhaps you could restrict the data you are pulling - whatever is time sensitive so that your pull will only get data that is older than 1 hour if your pull takes 45 minutes. Or to make things a little safer - how about just pulling the day before?
I believe SSIS 2008 has a new module called 'maintain' table that does the common task of getting updated/inserted records and optionally deletes.
Look into DTS, Microsoft's ETL tool. It's rather nice. Do the mapping, schedule it as a cron job, and Bob's your uncle.
Regardless of how you do the import to SqlServer from the MySQL clone, I don't think you need to worry about restricting MySQL replication to specific times.
MySQL replication only requires one thread in the master server and basically just transfers the transaction log to the slave. If you can, put the master and slave MySQL servers on a private LAN segment so that replication traffic does not impact the web traffic.
if you have SQL Server Standard or higher, SQL Server will take care of all of your needs.
use ssis to grab the data
use agent to schedule your timed tasks
btw - I'm doing the exact same thing that you are doing. SQL Server is awesome - it was easy to setup (I'm a noob to SSIS) and it worked on the first shot.
It sounds like what you need to do is to set up a script to start and stop replication on a slave database. If you can do that via a script, then you can establish a workflow in SSIS such as follows:
Stop Replication to Slave MySQL Database
If Replication has Stopped, then Take Snapshot of Slave MySQL Database
If Snapshot has been Taken, then
a= Start Replication to Slave MySQL Database
b= Import Slave MySQL Database Replica into SQL Server
NB: 3a and 3b can run in parallel.
I think your best bet in such a scenario would be to use SSIS to enable and disable MySQL database replication to the slave as well as to take a snapshot of the slave database. Then you can drive the whole thing from the SQL Server Agent mechanism.
Hope this helps