Galera Cluster for MySQL is a true Multimaster Cluster based on synchronous replication.
Questions tagged [galera]
124 questions
2
votes
1 answer
Galera Rsync SST Secured via SSL/SSH
Is it possible to secure Galera Cluster SST via rsync with SSL/SSH? This page suggests it is not, specifically the following quote:
Unlike rsync, xtrabackup includes support for SSL encryption built in.
I have followed all the steps to secure the…
Andrew Ensley
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2
votes
1 answer
How to share local IP within a cluster if server is bound to one IP?
I have a cluster with 3 nodes running in VMs on test setup. Now I want to take it to production and rented 3 dedicated root servers at Hetzner Online connected by a switch.
As I found out, they do not offer anymore shared IP and instead bind a…
merlin
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2
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2 answers
What would be a stable, failproof, scalable galera cluster implementation
Context: We are using a MariaDB Gallera cluster with (only) 2 master nodes for a web application. Last night we had a power failure and now we can't seem to recover the data and found out the database was corrupt on both nodes. Our initial…
Malitta N
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2
votes
1 answer
How to monitor MariaDB Galera cluster status from command line
I know to check the Galera cluster status, the command that should be used after login to the mysql client is:
SHOW STATUS LIKE 'wsrep%';
but, how to get the output directly from the command line?
The command below result in error:
[root@mariadb01…
Sharuzzaman Ahmat Raslan
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2
votes
1 answer
Deadlock trigger on MariaDB Galera cluster
I can trigger a deadlock on our (test) Galera cluster when updating a row with the same data.
INSERT INTO test (id, val) VALUES (1, 42), (2, 47);
-- Query OK, 2 rows affected (0.01 sec)
-- Records: 2 Duplicates: 0 Warnings: 0
Updating a value to…
Gert
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2
votes
0 answers
Galera cluster node fails with "InnoDB: Conflicting lock on table" error
I have a Galera Cluster (MariaDB 10.5) that consists of 3 nodes (one of which is Arbitrator).
Last week I have two incidents: both nodes just stopped responding and the following was found in logs:
2023-04-10 23:35:42 1 [ERROR] InnoDB: Conflicting…
Vladimir Ivanenko
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2
votes
2 answers
kubernetes mariadb-galera cluster - bitnami helm chart - Readiness probe failed
I am trying to setup a mariadb-galera cluster through the bitnami helm chart in my kubernetes cluster (1 master, 3 nodes). I have modified the myvalues.yaml to include an existingClaim: dbstorage and the storageClass: "nfs-storage". The image…
realShadow
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2
votes
0 answers
WireGuard Failover for MySQL Galera Cluster
I'm setting up four servers across four locations in an attempt to create a geo-redundant MySQL Galera cluster. Two of the servers are behind NAT, and I'm currently attempting to use WireGuard to overcome this inconvenience.
Servers one and two are…
TecumTechCEO
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0 answers
How can I use garbd+mariabackup to back up a MariaDB/Galera cluster?
I'm migrating a Galera cluster from MySQL to MariaDB 10.3.27, and as part of the process I'd like to change the backup method from the somewhat fiddly (and blocking) garbd+rsync to garbd+mariabackup. Changing the SST method to mariabackup worked…
mbethke
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Galera replication when two nodes can't communicate
Let's say I have a 3 nodes Galera cluster with MariaDB composed of servers A, B and C. Server A and server B can't communicate between each other but both servers can communicate with Server C. How would the cluster react to this situation ?
From…
Ror
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2
votes
1 answer
Several MaxScale instances connected to one MariaDB Galera Cluster
In short, I have one MariaDB Galera Cluster consisting of 3 nodes.
I have 3 independent servers on which MaxScale running.
Are there any disadvantages to connecting three independent MaxScale instances to a single database cluster?
Should I pay…
LubieCiastka
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1
vote
0 answers
Εxponentially growing Innodb_row_lock_time on "master" node of MariaDB 10.3 Galera cluster
I've been trying to investigate issues with an application failing, and I have reason to believe that the culprit lies somewhere in the database backend. To this end, I started collecting metrics from the backend MariaDB Galera cluster (currently…
gedia
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1
vote
1 answer
Can a galera node weight (pc.weight) be a non-integer?
In a MariaDB Galera cluster, you can assign a weight to each node, from 0-255. However, the documentation does not specify if this is allowed to be a decimal number (like 1.5). In other areas, it does specify when something must be an integer,…
Stephen S
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vote
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How likely is a Split Brain situation when dealing with Galera clusters?
Assuming I have a server setup where a quorum vote is always satisfied, how likely will a Split Brain situation occur with Galera? My understanding is Galera does its best to avoid it, but does that mean there's 0 chance of it ever happening if the…
Phil
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vote
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Mariadb 10.1 - 1 of 3 nodes will not restart
Here is the scenario, had to make a config change to Mariadb in a 3 node cluster. I edited the config file, and shut down the node with:
# service mysqld stop
Made the change on the other 2 nodes and did the same. When I started the most advanced…
Marc
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