# Weka containers architecture overview

The servers in a Weka system are members of a cluster. A server includes containers running software instances called processes that communicate with each other to provide storage services in the cluster.

Processes are dedicated to managing different functions as follows:

* Drive processes for SSD drives and IO to drives. Each drive process requires a dedicated core.
* Compute processes for filesystems, cluster-level functions, and IO from clients. Each compute process requires a dedicated core.
* Frontend processes for POSIX client access and sending IO to the compute and drive processes. Each frontend process requires a dedicated core.
* A management process for managing the overall cluster. The management process does not require a dedicated core.

In the Weka cluster, each server includes multiple containers in which each container runs processes of a specific type: drive, compute, or frontend. This deployment is known as **multi-container backend** architecture (MCB).

<figure><img src="https://661826007-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FuOB5D2WMRjXBnChPFTrk%2Fuploads%2FK02Zm7oSYBLggTh5wR0O%2FMCB_arch_4.2.png?alt=media&#x26;token=5b959587-a2b3-464d-82bc-5b2c07bc3309" alt=""><figcaption><p>Multi-container backend architecture (MCB)</p></figcaption></figure>

With MCB, a server can have multiple containers per process type. The containers are not limited to running the same software version and enable non-disruptive upgrades. The server can use the maximum available cores, allowing flexibility in the hardware cores' usage.

The benefits of using the MCB architecture include:

* **Support non-disruptive upgrades:**
  * Each container can have a different version and be installed separately from the other containers.
  * You can roll back each upgraded container separately.
  * Can access the network control plane seamlessly during the upgrade.
* **Effective use of the hardware:**
  * The number of cores that can be used in the server is no longer limited to 19. A server can include more than one container, each for a dedicated process type with up to 19 processes.
* **Less disruptive maintenance:**
  * Ability to stop the compute and frontend processes while running the drive processes.

{% hint style="info" %}
**Note:** The legacy architecture, where each server in the cluster includes a single container with all the processes running on it, is deprecated. Contact the Customer Success Team to convert from the legacy architecture to MCB.
{% endhint %}

{% hint style="info" %}
**Note:** Multi-container backend architecture is not supported yet on AWS using the CloudFormation, as well as in a system with Intel E810 NIC.
{% endhint %}

**Related topics**

[quick-install-guide](https://docs.weka.io/4.0/getting-started-with-weka/quick-install-guide "mention")

[using-cli](https://docs.weka.io/4.0/install/bare-metal/using-cli "mention")