I am designing a data replication solution across timezones and have run into the issue where I can only run and old version of MySQL (5.6) in one location, whereas the other two have MariaDB 10.2.
Now, I have read the information about Replication Compatibility over at MariaDB. Clearly I can't use MariaDB as a master and MySQL as a slave.
Intermediate solution based on Bash scripts
Yet, I want to use my EU server as a master and that is running MariaDB. So I'm now contemplating a way around the limitation. So far I have come up with an intermediate data storage solution in the overseas server, where data is shuffled periodically using my own Bash data migration scripts over a low bandwidth link.
MariaDB is required in the primary location
I have to use MariaDB in my primary location because I'm using the ColumnStore database there. That is unconditional as part of the application design.
Does this situation ring a bell?
Do you have experience with similar situations and would you mind sharing some inspiration as for how you did it?
My best solution so far is with Bash scripts that are cronned, where MySQL data is dumped (mysqldump) and transferred over a low bandwidth link, then merged with the master (ColumnStore storage engine). I'm looking at a T+1 data lag between my primary location and the secondary location that is running MySQL.
Any high level design thoughts or shared experience is highly appreciated.
Best regards
Related
My company uses a product that uses MySQL 5.5 for its backend database. The product automatically installs and configures MySQL during it's installation process. The product can be configured to run in a Hot Standby Redundant configuration. In these cases, the same installation process is performed on 2 separate servers and then during the products initial configuration redundant mode is selected. The product internally handles all the processes of duplicating the database data and keeping the 2 databases in sync. MySQL has know knowledge of the redundant setup. The MySQL installation on both server are identical, same location and same structure. The product does not have a very elegant/efficient way to sync a large, say 300G is size with 3K tables, database from the Primary server to the Backup server in cases where this is required, such as when creating a redundant system from a Single/Primary server config that has already been running for a while. My question is as follows.
Is there a safe/supported way to just manually copy the database/files from the Primary server to the Backup server considering that the MySQL installation on both servers are identical? BTW, this is on Production Windows Servers. I know I can do a full Export of the database from the Primary and then Import it on the BU server, but this can take hours. I am hoping there is a faster supported way to just copy the files from one server to the other, but in researching this I see conflicting info.
System Info
Windows
MySQL 5.5
Identical installation on both servers
"C:\ProgramData\MySQL\MySQL Server 5.5\data"
Innodb
File per table = true
Thanks in advance for any advice.
I once tried to just copy the Database Folder that contains all the innodb table files, "C:\ProgramData\MySQL\MySQL Server 5.5\data\Mydbase", from one server to another but mysql would not start up and had errors.
Yes: shut down the MySQL Server service on both computers. Then you can move the files in the datadir in any way you want. But this incurs some downtime while you do the file transfer.
If you must have no downtime, it's also possible, but requires more steps.
What I do is use Percona XtraBackup to make a physical backup of the source instance, but this won't work as easily for you because you are on Windows. XtraBackup doesn't work on Windows. Some people use tricks to run XtraBackup in a Docker container on Windows.
Then restore the XtraBackup to your new computer in the normal way, and configure it as a replica of the source instance. See https://docs.percona.com/percona-xtrabackup/8.0/howtos/setting_up_replication.html
By making the new instance a replica, you can let it get updated with the most recent changes that have occurred on the source instance while you were setting up the replica.
Then at some point you decide to switch to the new instance. Then you set the source instance to read-only mode, to prevent client applications from making any new changes. Let the replica catch up with the last final changes (this should only take a second if the replica was keeping up with changes already). Now you can change your client applications to use the replica instead of the former source. Then un-configure replication on the new instance with RESET SLAVE because the last thing you want is for any more changes to occur on the former source and replicate to the new instance.
If you try this procedure, I suggest you test it on a test instance — NOT your production instance — until you are comfortable with the tools.
P.S.: In addition to not supporting Windows, I have no idea if the current version of XtraBackup works with MySQL 5.5. That version was released in 2010, and reached its end of life in 2018. So I think you will need to research which version of XtraBackup still can read a MySQL 5.5 instance. You might have to use an old version of XtraBackup.
I have aws rds aurora database for the production environment. And I have to build a database for the development environment.
I tried it by using aws database migration service(DMS), snapshot, mysqldump.
First, DMS didn't support migrating Auto_Increment column and Indexes. But I need them.
Second, Snapshot overwrite production database's user data(MySQL user data - using when connecting to MySQL) to the development database. And I want to maintain them differently.
Last, mysqldump is so slow and I concerned about mysqldump may cause down performance to production database.
So, I'm looking for the other way.
The below things are what I want:
Every information(w/o MySQL user data) such as Auto_Increment, Indexes are must be migrated.
Development environment database is must be sync to production database(reset and re-migrate) every day automatically.
Migration process as faster and lower downing performance as possible is the best.
Does anyone know how to build it?
Using an AWS DMS task, you can specify what schema to migrate and the type of migration.
The page should look similar to the following
Amazon RDS automatically creates a primary
DB Instance and synchronously replicates the data to a standby instance in a different
Availability Zone (AZ). Each AZ runs on its own physically distinct, independent
infrastructure, and is engineered to be highly reliable.
Yes you can. Migrations are among the most time-consuming tasks handled by the database
administrators (DBAs). Although the task becomes easier with the advent of
managed migration services such as the AWS Database Migration Service (AWS
DMS), many large-scale database migrations still require a custom approach
due to performance, manageability, and compatibility requirements.
Extra
*Amazon RDS provides high availability and failover support for DB instances using Multi-AZ- deployments.
*ElastiCache improves the performance of your database through caching query results
Please forgive my ignorance but I do not have a ton of experience with MySQL. I am a web developer but overall I have pretty much just installed MySQL or spun up an RDS instance, connected to it and everything just works. However I am currently being tasked with creating a complete backup of our primary server (essentially high availability with a load balancer etc). So I thought now might be a good time to change how I haver our MySQL setup to take advantage of having 2 servers. Currently our MySQL lives on our primary servers and that will probably stay that way for now, however my goal with this new setup is to have 2 identical servers, both running the application and both having the exact same MySQL data structure / data. I want to be able to essentially open up the web application on one server, make a change, see it on the other or vica versa.
From my research it looks like what I want is called "Master-Master Replication" however it seems as if this is an older / more outdated approach? Every article I read is from ~2010-2012 and most people say it is depreciated and I should use Percona XtraDB Cluster, MySQL Group Replication, or Galera Cluster etc. I basically have no idea what any of that means and I am looking for the easiest way to get Master-Master type setup working. On top of that even if I wanted to use regular Master-Master replication it seems as if this is something specific to MySQL and not Percona which is what I actually use.
I know plenty about dev ops and can get everything but the MySQL up and running in no time but I would love some insight on the best way to do this. Currently servers are running Centos 7, Percona 5.7, Apache 2.4.
The easiest way to start is to setup a percona xtradb cluster with proxysql.
Percona xtradb cluster handles all the problems that are present in basic MySQL Master-Master Replication.
Both Galera and Percona Xtradb CLuster are same, as they use the same galera plugin, Only that Percona has customized it and added some extra features like in built proxysql( kind of load balancer for database).
Let's clear up one thing first. Percona is MySQL. If a feature is available on Oracle MySQL (the community version is what I am referring to here), then it is also available on Percona. Think of the two like a cake: MySQL is the base "cake" and Percona is the frosting/sprinkles/etc that go on top.
That being said you can absolutely do Master/Master using Percona MySQL. The standard/best practice is to configure this in active/hot-standby. Meaning, do not write to both nodes at the same time. Your application, or your middleware/proxy, must isolate writes to only one node. This will save you insane headaches when/if replication breaks.
ProxySQL is not a Percona product, but we do support it 100%. You can place ProxySQL in front of your M/M and setup the correct query rules to only route to one MySQL.
You are correct that the most modern solution here, and in my opinion, an easier solution, is to set up a 3-node Percona XtraDB Cluster (PXC). Again, Galera MySQL is the "cake" and PXC is all the extras on top. Group Replication is pie (just to continue the analogy.)
We consider a 3-node PXC fronted with ProxySQL to be one of the best HA solutions out there for MySQL. It is still best practice to only write to one node, and utilize the other 2 for read-only queries. If the primary node goes down, each of the other two have an up-to-the-transaction copy of the data. Again, ProxySQL helps route the traffic if primary goes down.
Backups can be taken from any PXC node using Percona XtraBackup in a non-blocking/hot fashion.
I've just setup MariaDB on Ubuntu VMs with Master-Master replication using a combination of these three guides:
http://www.chriscouture.com/setting-up-replication-on-mariadb/
https://www.server-world.info/en/note?os=Ubuntu_16.04&p=mariadb&f=3
https://www.digitalocean.com/community/tutorials/how-to-set-up-mysql-master-master-replication
In short, both are masters and both are slaves to the other one. This will be used by separate web hosting servers. One will be "primary master" which all web servers connect to, and in case of a failure on that server they will be manually changed to the "secondary master".
The reason I went for this instead of Master-Slave is
The 3rd party backup job is simpler. Both backups and restores are done on the "secondary" master, instead of backup from the secondary and restoring to the primary.
If the primary fails and I have to switch to the secondary for a while, all changes made during that time should be written to the primary when it comes online again (?).
It's not live yet but everything works fine so far when I'm testing it. However I'm no DBA. I've been reading about how it's not "worth it" and if you don't absolutely need the Master-Master you should go with Master-Slave.
Now I'm afraid I will run into problems like inconsistencies and other headaches.
A maximum of about 100 databases for mostly Wordpress installations will be hosted.
What are your thoughts on the matter? M-M or M-S?
If M-S, how do I "sync back" data changed if the Master goes down and the Slave need to be the active server for a period of time?
I'm also wondering if there's a standard, generally accepted, step-by-step way to upgrade these. I'm thinking when a OS or MariaDB version upgrade is needed.
My general thoughts are something like take down one server, upgrade it, start it. Then take down the other, upgrade it, start it.
But I'm guessing there's more to it than that.
I only found some documentation on M-S upgrading with Mysql.
I maintain a server that runs daily cron jobs to aggregate data sources and generate reports, accessible by a private Ruby on Rails application.
One of our data sources is a partial dump of one of our partner's databases. The partner runs an active application and the MySQL DB has hundreds of tables. They have given us read-only access to a relatively underpowered readonly slave of their application DB.
Because of latency issues and performance bottlenecking on their slave DB, we have been maintaining a limited local copy of their DB. We only need about 20 tables for our reports, so I only dump those tables. We also only need the data to a daily granularity, so realtime sync is not a requirement.
For a few months, I had implemented a nightly cron which streamed the dump of the necessary tables into a local production_tmp database. Then, when all tables were imported, I dropped production and renamed production_tmp to production. This was working until the DB grew to over 25GB, and we started running into disk space limitations.
For now, I have removed the redundancy step and am just streaming the dump straight into production on our local server. This feels a bit flimsy to me, and I would like to implement a safer approach. Also, currently doing the full dump/load takes our server over 2 hours, and I'd like to implement an approach that doesn't take as long. The database will only keep growing, so I'd like to implement something future proof.
Any suggestions would be appreciated!
I take it you have never heard of, or considered MySQL Replication?
The idea is that you do your backup & restore once, and then configure the replica to "subscribe" to a continuous stream of changes as they are made on the primary MySQL instance. Any change applied to the primary is applied automatically to the replica within seconds. You don't have to do the backup & restore procedure again, unless the replica gets damaged.
It takes some care to set up and keep working, but it's a much more efficient method of keeping two instances in sync.
#SusannahPotts mentions hot backup and/or incremental backup. You can get both of these features for free, without paying for MySQL Enterprise using Percona XtraBackup.
You can also consider using MySQL Transportable Tablespaces.
You'll need filesystem access to run either Percona XtraBackup or MySQL Enterprise Backup. It's not possible to use these physical backup tools for Amazon RDS, for example.
One alternative is to create a replication slave in the same network as the live system, and run Percona XtraBackup on that slave, where you do have filesystem access.
Another option is to stream the binary logs to another host (see https://dev.mysql.com/doc/refman/5.6/en/mysqlbinlog-backup.html) and then transfer them periodically to your local instance and replay them.
Each of these solutions has pros and cons. It's hard to recommend which solution is best for you, because you aren't sharing full details about your requirements.
This was working until the DB grew to over 25GB, and we started running into disk space limitations.
Some question marks "here":
Why don't you just increase the available Diskspace for your database? 25 GB seems nothing when it comes down to disk-space?
Why don't you modify your script to: download table1, import table1_tmp, drop table1_prod, rename table1_tmp to table1_prod; rinse and repeat.
Other than that:
Why don't you ask your partner for a system with enough performance to run your reports on? I'm quite sure, he would prefer this rather than having YOU download sensitive data every day to your "local site"?
Last thought (requires MySQL Enterprise Backup https://www.mysql.de/products/enterprise/backup.html):
Rather than dumping, downloading and importing 25 GB every day:
Create a full backup
Download and import
Use Differential or incremental backups from now.
The next day you download (and import) only the data-delta: https://dev.mysql.com/doc/mysql-enterprise-backup/4.0/en/mysqlbackup.incremental.html