+++ title = "Composite clusters" +++
Composite clusters
The ipfs-cluster-service process provides a Proxy-To-IPFS endpoint, which effectively allows a cluster peer to present itself as if it were an IPFS daemon. This allows to use a cluster peer (from a different cluster) instead of an IPFS daemon, giving origin to the composite clusters idea.
The IPFS Proxy
The IPFS Proxy is an endpoint which presents the IPFS HTTP API in the following way:
- Some requests are intercepted and trigger cluster operations
- All non-intercepted requests are forwarded to the IPFS daemon attached to the cluster peer
This endpoint listens by default on /ip4/127.0.0.1/tcp/9095 and is provided by the ipfshttp connector component.
The requests that are intercepted are the following:
/add: the proxy adds the content to the local ipfs daemon and pins the resulting hash[es] in cluster./pin/add: the proxy pins the given CID in cluster./pin/rm: the proxy unpins the given CID from cluster./pin/ls: the proxy lists the pinned items in cluster./repo/stat: the proxy responds with aggregated/repo/statfrom all connected IPFS daemons.
Responses from the proxy mimic the IPFS daemon responses, thus allowing to drop-in this endpoint in places where the IPFS API was used before. For example, you can use the go-ipfs CLI as follows:
ipfs --api /ip4/127.0.0.1/tcp/9095 pin add <cid>ipfs --api /ip4/127.0.0.1/tcp/9095 add myfile.txtipfs --api /ip4/127.0.0.1/tcp/9095 pin rm <cid>ipfs --api /ip4/127.0.0.1/tcp/9095 pin ls
The responses would come from cluster, not from go-ipfs. The intercepted endpoints aim to mimic the format, headers and response codes from IPFS. If you have custom headers configured in IPFS, you will need to add their names them to the ipfsproxy.extract_headers_extra configuration option.
A Cluster of Clusters
As mentioned above, the Proxy endpoint allows to create a cluster of clusters. This would be one of the common topologies that can be achieved, with the main cluster in the middle and 3 sub-clusters attached:
