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Dfcache

dfcache is the cache client to of dragonfly that communicates with dfdaemon and operates on files in P2P network, and it can copy multiple replicas during import. P2P cache is effectively used for fast read and write cache.

Usage​

Import a file into Dragonfly P2P network.

dfcache import <PATH>

Export a file from Dragonfly P2P network.

dfcache export <ID> -O <OUTPUT> <PATH>

Get file information in Dragonfly P2P network.

dfcache stat <ID>

Example​

Import​

dfcache import /tmp/file.txt

Configuring persistent replicas and TTL​

Use the following parameters to specify the number of replicas and ttl of the persistent cache task.

dfcache import --persistent-replica-count 3 --ttl 2h /tmp/file.txt

Importing large file​

The default ID is calculated based on the file's SHA256. For large files, this process may take longer. You can specify --content-for-calculating-task-id to define the file's uniqueness. For example, --content-for-calculating-task-id can be set to the filename, provided it ensures uniqueness.

dfcache import --content-for-calculating-task-id <CONTENT_FOR_CALCULATING_TASK_ID> /tmp/file.txt

Export​

dfcache export <ID> -O /tmp/file.txt

Export in Container​

Install Dragonfly in the Kubernetes cluster​

Deploy Dragonfly components across your cluster:

helm repo add dragonfly https://dragonflyoss.github.io/helm-charts/
helm install --create-namespace -n dragonfly-system dragonfly dragonfly/dragonfly

For detailed installation options, refer to Helm Charts Installation Guide.

Mount the Unix Domain Socket of dfdaemon to the Pod​

Add the following configuration to your Pod definition to mount the Dragonfly daemon's Unix Domain Socket, then the container can use the same dfdaemon to export files in the node.

apiVersion: v1
kind: Pod
metadata:
  name: runtime
spec:
  containers:
    - name: runtime
      image: your-image:tag
      volumeMounts:
        - mountPath: /var/run/dragonfly
          name: dfdaemon-socket-dir
  volumes:
    - name: dfdaemon-socket-dir
      hostPath:
        path: /var/run/dragonfly
        type: DirectoryOrCreate
Install dfcache in the Container Image​

Install dfcache in the Container Image, refer to Install Client using RPM or Install Client using DEB.

Export via UDS(unix domain socket) of dfdaemon in the node​

Once set up, use the dfcache command with the --transfer-from-dfdaemon flag to export files:

dfcache export --transfer-from-dfdaemon <ID> -O /tmp/file.txt

Stat​

dfcache stat <ID>

Log​

1. set option --console if you want to print logs to Terminal
2. log path: /var/log/dragonfly/dfcache/