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5 votes
Accepted

How likely is a Split Brain situation when dealing with Galera clusters?

I assume you have a 3-node system with no weightings and the nodes are in separate geographical locations? Split brain usually happens when these two things occur: One node dies, and before you can ...
Rick James's user avatar
  • 2,533
4 votes

How to "safely" shutdown/restart a Galera cluster?

I know it is late reply to this question. But just in case any one looking for the exact answer about how to safely shutdown and restart the mariadb galera cluster. For example we have three mariadb ...
Milad Hamid Elhaei Sahar's user avatar
3 votes

Why is keepalived running two MASTER nodes in my Sticky VIP configuration?

Single word answer: iptables. I was running two instances of keepalived - one to allow access from inside networks and the other to support external access. I copied the internal configuration to ...
Mark's user avatar
  • 131
3 votes

Does a Galera equivalent for Postgres exist?

While looking for the same, I stumbled upon the very interesting stolon project, which announces itself as "PostgreSQL cloud native High Availability and more" and includes walkthroughs for setting ...
gandhiano's user avatar
3 votes
Accepted

Galera cluster (MariaDB) on Docker/CoreOS: second node doesn't work on first attempt

After days of fighting with this, I was finally able to get this to work. The key issue is that the default Docker image (probably mimicking what the MySQL image does) adds timezone data in the ...
ItalyPaleAle's user avatar
3 votes
Accepted

unable to run a mariadb 10.1 galera cluster

I have solved the issue, I am using centos7 and i had to: 1.) add this in /etc/my.cnf.d/server.cnf [mysqld] bind-address=0.0.0.0 [galera] wsrep_on=ON wsrep_provider=/usr/lib64/galera/libgalera_smm....
simonC's user avatar
  • 195
3 votes
Accepted

Transform Galera cluster into single node mariadb server

It's easy. You should gracefully stop all nodes. After this remove all Galera configuration from my.cnf and start MySQL. Better to do it on latest stopped node, to prevent dataloss.
Alexander Tolkachev's user avatar
2 votes
Accepted

2-host MariaDB Galera cluster with keepalived only, no HAproxy?

Yes, a virtual IP should be enough. However, you should have a third host running at least Galera arbitrator daemon, which takes care of quorum, that is deciding which one of the two nodes is the one ...
Tero Kilkanen's user avatar
2 votes
Accepted

How to "safely" shutdown/restart a Galera cluster?

For a graceful shutdown of the cluster, first verify status of your cluster. For each node check the status. Then if the status is synced then you can shut down the node one at a time. What is tricky ...
Tux_DEV_NULL's user avatar
  • 1,103
2 votes
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Several MaxScale instances connected to one MariaDB Galera Cluster

Update: With the cooperative monitoring added in MaxScale 2.5, it is safe to use automatic failover with multiple MaxScale instances even with asynchronous replication clusters. There should be no ...
markusjm's user avatar
  • 328
2 votes

Galera cluster up sync but missing variable wsrep_cluster_size

No worries now. I called the wrong SQL command before, it should be GLOBAL STATUS: SHOW GLOBAL STATUS LIKE 'wsrep_%';
James's user avatar
  • 131
2 votes

MariaDB galera cluster, add node without interruption

In general you don't need to do this. When cluster is running it discovers all other nodes dynamically from any node it connects first, so you specify just any joined node(s) in this setting: The new ...
Nikita Kipriyanov's user avatar
2 votes
Accepted

Mariadb Galera Cluster Cannot Start Up

If Node2 and Node3 were stopped, unless you changed something in the quorum weights Node1 will not be in good shape. I'd recommend you do the following (assuming Node3 is still down): Stop Node2 Stop ...
KrisVandenbergh's user avatar
1 vote
Accepted

MariaDB 10.3.10 Galera Cluster not syncing InnoDB table definition

MyISAM tables are not replicated by Galera. Some system tables, (most of the tables in the mysql database) are MyISAM. When upgrading, mysql_upgrade must be run. mysql_upgrade often makes changes to ...
Rick James's user avatar
  • 2,533
1 vote

How to recover Galera cluster node

Solved. The crashed node was configured to use a different SST method to the donor node. It previously used Percona xtrabackup and through accident or stupidity the configs were out of date.
Tim's user avatar
  • 594
1 vote

mysql (Perconadb) Galera/Xtrabackup cluster join fails with "Invalid Argument"

I find that the reasons SST fails regularly falls under one of the following: SElinux/AppArmor is Enforcing, SST user was not created on donor node (and permissions not updated correctly in .cnf files)...
utdrmac's user avatar
  • 111
1 vote

Galera or master/slave MariaDB

I think you are a bit confused as to what Galera is and what it isn't. Galera is a multi-master replication system that allows 2 (preferably 3) or more nodes to replicate data amongst themselves and ...
Miuku's user avatar
  • 820
1 vote
Accepted

MariaDB Galera cluster - 3rd node can not start/connect

For me the fix was simply to tear down the entire cluster and start it back up. on each node: service mysql stop On the most advanced node # galera_new_cluster On each subsequent node service ...
Marc's user avatar
  • 33
1 vote
Accepted

Different InnoDB data file sizes on Galera

I found an explanation here: https://stackoverflow.com/questions/27146497/can-database-size-be-different-on-different-node-in-mairadb-galera-cluster Because it's logical replication, rewriting ...
greenweeds's user avatar
1 vote

Initial Xtradb Cluster setup -- each node comes up isolated

I think your problem might be: 2017-11-15T15:23:20.516889Z 0 [Note] WSREP: gcomm: connecting to group 'pxc-cluster', peer '' Assuming this is your second node and your first node is configured with: ...
Jervin Real's user avatar
1 vote
Accepted

how mariadb galera can help me scale writes?

Distributed reads. Most DBs read much more then they write. This reduces overall IO load on the nodes. High availability Distributed writes are potentially much faster on the replicated nodes, as ...
Sven's user avatar
  • 99.3k
1 vote

how mariadb galera can help me scale writes?

In short: it doesn't. As you have already noted, every write has to be done on every node. If you want to scale writes you might want to look into sharding over multiple clusters or scaling your ...
Christopher Perrin's user avatar
1 vote
Accepted

setting up MariaDB Galera cluster Ubuntu Zesty

It looks like your cluster configuration is missing a few things: wsrep_provider should be set to the path to the Galera wsrep library wsrep_on should be set to "ON". It looks like you actually need ...
Jenos's user avatar
  • 646
1 vote

Galera Node won't start after recovery

You should be clearer in your question. As per your question here, but not stated above, you have 1 node which appears to be working and are in the process of adding a second node. You are getting ...
DBAaron's user avatar
  • 11
1 vote

Galera Node won't start after recovery

Sorry but I am confused. you have 3 nodes say node-1, node-2, node-3. As per your information node-1 is up and running and you are trying to add node-2. (Log that you have shared is for node-1 ? Is ...
Krunal's user avatar
  • 11
1 vote

mariadb galera cluster don't intialize on debian wheezy

You need to bootstrap the cluster first with either node having the following cluster option: wsrep_cluster_address="gcomm://" So, start one node with that configuration, then start the other node ...
Tero Kilkanen's user avatar
1 vote
Accepted

Unable to connect to mysql DB through my HA Proxy Servers [Keepalived is used for Virtual IP-VIP]

The mistake I did was using wrong IP Addresses of my HA-Proxy Servers while granting privileges in mysqldb, once I gave right IP Addresses, it worked without any issues.
karthik v's user avatar
  • 191
1 vote
Accepted

Couldn't join MariaDB Galera Cluster node back to cluster after software update. wsrep_* options in my.cnf seem to be ignored

As I found, new option appeared in a new version of MariaDB: wsrep-on. It wasn't needed before. I added that option to config file, it ceased ignoring my wsrep settings. It started a server for a ...
Nikita Kipriyanov's user avatar
1 vote
Accepted

WSREP: Bad value for 'socket.ssl_key'

My permissions were off. This fixed it: root@server:/etc/mysql# chmod 500 /etc/mysql/ssl/ root@server:/etc/mysql# chmod 400 /etc/mysql/ssl/* root@server:/etc/mysql# chown -R mysql:mysql /etc/mysql/...
Andrew Ensley's user avatar

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