# Cluster configuration/ setup

**URL:** <https://forums.percona.com/t/cluster-configuration-setup/9540>\
**Category:** Percona XtraDB Cluster 8.x\
**Created:** [March 4, 2021, 9:45am UTC](https://forums.percona.com/t/cluster-configuration-setup/9540 "2021-03-04T09:45:39Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![staun](https://avatars.discourse-cdn.com/v4/letter/s/58f4c7/32.png) [@staun](https://forums.percona.com/u/staun)\
**Post date:** [March 4, 2021, 9:45am UTC](https://forums.percona.com/t/cluster-configuration-setup/9540/1 "2021-03-04T09:45:39Z")

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After some time I have now managed to get a working cluster in a test-enviroment and want to proceed. But have a little question regarding the setup.

I have our Main office, 3 regional sites.

I had hoped that I could have 1 server in our Main site, and each site connected to this server. I have 2 servers on each site so they can continue operations in case of WAN disconnect.

What I discovered is that, each site is also trying to replicate to the other sites (which makes sense, but not what I wanted)  
I want each site to replicate only to the main site. Is this not possible? Do I have to create a server on the main site for each sub site we have or is possible to run several clusters on a single Main-server?  
(the subsites are configured to contact MainSite and local site only in mysql.conf, but the main server have all site servers listed in gcomm://)

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**Author:** ![matthewb](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/matthewb/32/34_2.png) [@matthewb](https://forums.percona.com/u/matthewb)\
**Post date:** [March 4, 2021, 1:21pm UTC](https://forums.percona.com/t/cluster-configuration-setup/9540/2 "2021-03-04T13:21:43Z")

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Percona XtraDB Cluster is exactly that, a cluster. Which means all nodes will accept writes and all nodes will synchronously replicate all transactions to every other node.

It sounds like what you want is to use is MySQL’s asynchronous replication and create a ‘fan-in’ topology. Something [like this](https://lh3.googleusercontent.com/-PjXfoGajrtg/VbpEvkxnPYI/AAAAAAAABtg/dwS0st_qQUU/s411-Ic42/topologies_fan-in.jpg)?

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<div class="post-metadata">

**Author:** ![staun](https://avatars.discourse-cdn.com/v4/letter/s/58f4c7/32.png) [@staun](https://forums.percona.com/u/staun)\
**Post date:** [March 4, 2021, 3:40pm UTC](https://forums.percona.com/t/cluster-configuration-setup/9540/3 "2021-03-04T15:40:26Z")

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Thanks for replying and yes it is very close. But I also need to write to the database on Host 4 on the illustration.

So I might have to create a server for each site I have, when I want this configuration.

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<div class="post-metadata">

**Author:** ![matthewb](https://sea1.discourse-cdn.com/flex019/user_avatar/forums.percona.com/matthewb/32/34_2.png) [@matthewb](https://forums.percona.com/u/matthewb)\
**Post date:** [March 4, 2021, 5:51pm UTC](https://forums.percona.com/t/cluster-configuration-setup/9540/4 "2021-03-04T17:51:02Z")

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As long as you are writing to different logical databases, you can write to all at any time.