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Hey <@U0A71G31CDV> Give me a complete Disaster re...
# questions-and-troubleshooting
m
Hey @Rocky Give me a complete Disaster recovery plan in shared-nothing architecture. Disaster plan in kubernetes level and in also starrocks cluster level.
r
A complete Disaster Recovery (DR) plan for a StarRocks shared-nothing architecture involves both the database layer and the underlying Kubernetes infrastructure. Because shared-nothing clusters rely on local storage for performance, your DR strategy must account for data replication, snapshotting, and cluster failover. ────────── 1. StarRocks Cluster Level (Shared-Nothing) In a shared-nothing architecture, BEs (Backend nodes) store data on local disks. DR is managed through internal high availability, snapshots, and cross-cluster replication. A. High Availability (RTO: Seconds) * Data Replication: Always set 
replication_num = 3
for all tables. This ensures that if a BE node or its disk fails, StarRocks automatically serves data from other replicas and initiates a background repair. * FE Quorum: Deploy at least 3 FEs (1 Leader, 2 Followers). This allows the cluster to survive the loss of one FE node via Raft-based leader election. B. Backup & Restore (RTO: Hours) Regular snapshots protect against data corruption or accidental 
DROP TABLE
commands. * Create a Repository: Link StarRocks to an external object store (S3, MinIO, or HDFS).
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    CREATE REPOSITORY my_s3_repo
    WITH BROKER
    ON LOCATION "<s3a://my-bucket/starrocks_backups>"
    PROPERTIES (
        "aws.s3.access_key" = "...",
        "aws.s3.secret_key" = "...",
        "aws.s3.region" = "us-east-1"
    );
* Schedule Backups: Use the 
BACKUP
command to create snapshots of critical databases or tables.
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    BACKUP SNAPSHOT sample_db.snapshot_label TO my_s3_repo;
* Restoration: In a total cluster failure, deploy a fresh cluster and run 
RESTORE
. C. Cross-Cluster Replication (CCR) (RTO: Minutes) For multi-region DR, maintain a Primary-Standby setup. StarRocks supports CCR to replicate data from a primary cluster to a standby cluster in near real-time. * Setup: Enable CCR on the Standby cluster to pull data from the Primary. * Failover: If the Primary goes down, redirect application traffic to the Standby cluster. ────────── 2. Kubernetes Level On Kubernetes, the StarRocks Operator manages the lifecycle. DR at this level focuses on infrastructure resilience. A. Multi-AZ Deployment * Anti-Affinity: Use Pod Anti-Affinity in your 
StarRocksCluster
YAML to ensure FE and BE pods are distributed across different nodes and Availability Zones (AZs). * StorageClass: Use an AZ-aware 
StorageClass
. For shared-nothing, local NVMe or high-performance EBS/PD with 
volumeBindingMode: WaitForFirstConsumer
is recommended. B. Persistent Volume (PV) Management * Reclaim Policy: Set the 
reclaimPolicy
to 
Retain
in your StorageClass. If a namespace is accidentally deleted, the data on the disks remains intact. * Volume Snapshots: If your CSI driver supports it, take periodic K8s Volume Snapshots. However, note that StarRocks' internal 
BACKUP
is more consistent for database recovery. C. FE Metadata Protection The FE metadata (BDB JE) is the "brain" of the cluster. * PV Backup: Ensure the FE's metadata directory (
/opt/starrocks/fe/meta
) is on a reliable Persistent Volume. * Manual Recovery: If the FE metadata is corrupted and the quorum is lost, use the 
bdbje_reset_election_group
configuration to force-start a single FE and reconstruct the cluster. D. Multi-Cluster DR (K8s level) * Global Load Balancer: Use a Global Server Load Balancer (GSLB) or Route53 to route traffic between StarRocks clusters in different K8s clusters/regions. * GitOps: Store your StarRocks Cluster CRD and configurations in Git (e.g., ArgoCD). This allows you to recreate the entire StarRocks environment in a new K8s cluster within minutes. ────────── 3. Disaster Recovery Matrix Scenario | Recovery Mechanism | Level Node/Disk Failure | Multi-replica (
replication_num: 3
) | StarRocks
Accidental Deletion | StarRocks 
RESTORE
from S3 Repository | StarRocks AZ Outage | Multi-AZ Anti-Affinity & FE Quorum | Kubernetes Region/K8s Failure | Cross-Cluster Replication (CCR) to Standby | Both Metadata Corruption | 
bdbje_reset_election_group
& Meta Backup | StarRocks Recommendations 1. Test your Restore: A backup is only as good as its last successful restore test. 2. Monitor Quorum: Use Prometheus/Grafana to alert if 
alive
FE or BE counts drop. 3. Version Consistency: Ensure the Standby cluster (for CCR) runs the same or a newer version of StarRocks as the Primary. References • deployment/sr_operator.md • deployment/helm.md
m
@Rocky How to get snapshot from fe meta automatically ??
r
To get FE metadata snapshots automatically in a StarRocks shared-nothing architecture, you can use the following methods depending on your version and environment. 1. Native Automated Cluster Snapshot (v3.4.2+) Starting from v3.4.2, StarRocks introduced a native feature to automatically back up both data and metadata to object storage. Even in shared-nothing, this is the most streamlined "automated" way. * How it works: Each time an FE completes a metadata checkpoint (creating a new metadata 
image
file), the system automatically triggers a snapshot and uploads it to your configured storage volume. * Enable it:
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    -- 1. Create a storage volume (S3/MinIO/GCS/HDFS)
    CREATE STORAGE VOLUME my_backup_volume
    TYPE = S3
    LOCATIONS = ("<s3://my-bucket/starrocks_backups/>")
    PROPERTIES ("aws.s3.region" = "us-east-1");

    -- 2. Enable automated snapshots
    ADMIN SET AUTOMATED CLUSTER SNAPSHOT ON STORAGE VOLUME my_backup_volume;
* Configuration: You can control the frequency using the FE parameter 
automated_cluster_snapshot_interval_seconds
(default is 600 seconds/10 minutes). 2. Kubernetes Level: Volume Snapshots (Recommended for K8s) Since you are on Kubernetes, the most robust way to back up FE metadata is to snapshot the Persistent Volumes (PVs) attached to the FE pods. FE metadata is stored in the 
/opt/starrocks/fe/meta
directory inside the pod. * Using Velero: Use Velero with the CSI plugin to schedule periodic backups of the entire StarRocks namespace. Velero will trigger snapshots of the FE PVs and store the metadata in object storage. * Native K8s VolumeSnapshot: If your StorageClass supports CSI snapshots, you can create a 
CronJob
in Kubernetes that periodically creates a 
VolumeSnapshot
resource for your FE pods.
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yaml
    # Example snippet for a VolumeSnapshot
    apiVersion: <http://snapshot.storage.k8s.io/v1|snapshot.storage.k8s.io/v1>
    kind: VolumeSnapshot
    metadata:
      name: fe-meta-snapshot-timestamp
    spec:
      volumeSnapshotClassName: csi-aws-vsc
      source:
        persistentVolumeClaimName: fe-meta-pvc-starrocks-fe-0
3. Sidecar "Sync" Method (Version Agnostic) If you are on an older version and cannot use VolumeSnapshots, you can add a sidecar container to your FE deployment (via the StarRocks Operator 
spec.starrocksFeSpec.sidecarContainers
). * Sidecar Logic: The sidecar runs a script that uses 
aws s3 sync
or 
gsutil rsync
to monitor the 
/opt/starrocks/fe/meta
directory and upload new 
image.*
files to object storage. * Triggering Images: You can force the FE to create a fresh metadata image periodically via a cron job that executes:
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sql
    ALTER SYSTEM CREATE IMAGE;
Summary of FE Meta Storage FE metadata consists of two main parts: 1. Image Files (
meta/image
): A full snapshot of the metadata at a specific point in time. 2. Edit Logs (
meta/bdb
): Incremental changes (journals) since the last image. Important: For a valid backup, you should at least have the latest image file. If you only have the image, you can restore the cluster to the state at the time the image was created. If you have both the image and the subsequent edit logs, you can restore to the latest state. References • administration/management/FE_configuration.md • administration/Meta_recovery.md • faq/operation_maintenance_faq.md
In a shared-nothing architecture, the "Automated Cluster Snapshot" feature (introduced in v3.4.2) is not supported, as it is currently exclusive to shared-data clusters. For shared-nothing clusters on Kubernetes, you must use a combination of database-level commands and infrastructure-level tools to automate FE metadata backups. 1. Kubernetes Level: Volume Snapshots (The Industry Standard) Since FE metadata is stored in a Persistent Volume (PV), the most reliable way to automate snapshots is at the storage layer using the Kubernetes CSI (Container Storage Interface). * Tool: Velero with the CSI plugin. * How it works: You schedule a Velero backup for the StarRocks namespace. Velero communicates with your cloud provider (AWS EBS, GCP PD, Azure Disk) to create a consistent point-in-time snapshot of the FE's 
meta
volume. * Automation:
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    # Schedule a daily backup of FE metadata volumes
    velero schedule create sr-metadata-daily --schedule="0 1 _ _ *" --include-namespaces starrocks --selector "<http://app.kubernetes.io/component=fe|app.kubernetes.io/component=fe>"
2. Database Level: Cross-Cluster Replication (CCR) If you need an "always-on" automated metadata backup, CCR is the best choice. It automates the replication of both data and metadata from a Primary cluster to a Standby cluster. * Benefit: The Standby FE is automatically kept in sync with the Primary. If the Primary fails, the Standby already has the metadata loaded. * Setup: Use the StarRocks CCR operator to link the two clusters. 3. Manual Automation via Sidecar (For Object Storage) You can automate the off-site backup of the metadata 
image
file by adding a sidecar container to your FE pods via the StarRocks Operator. 1. Trigger Image Creation: Use a CronJob to periodically run the following SQL to ensure the latest metadata is written to disk:
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    ALTER SYSTEM CREATE IMAGE;
2. Sync to S3/Cloud Storage: Use a sidecar container (e.g., with 
rclone
or 
aws-cli
) that monitors the 
/opt/starrocks/fe/meta/image
directory and uploads new files to a bucket. _ _Configuration in StarRocksCluster CRD:*
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yaml
        spec:
          starrocksFeSpec:
            sidecarContainers:
              • name: metadata-uploader
                image: amazon/aws-cli
                command: ["/bin/sh", "-c"]
                args: ["while true; do aws s3 sync /opt/starrocks/fe/meta/image <s3://my-backup-bucket/fe-meta;> sleep 3600; done"]
                volumeMounts:
                  • name: fe-meta
                    mountPath: /opt/starrocks/fe/meta
4. Backup & Restore (Table Data Only) Note that the StarRocks 
BACKUP
command primarily backs up table data and schema, not the entire FE system state (like users, permissions, or global variables). * To automate table-level backups, use a 
CronJob
that calls a script to run:
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sql
    BACKUP SNAPSHOT db_name.snapshot_label TO my_repo;
Summary Recommendation * For pure metadata DR: Use Velero or CSI Snapshots of the FE Persistent Volumes. It is the most robust K8s-native way. * For high-end DR (RTO < 5 mins): Use CCR to maintain a live standby cluster. * For shared-data clusters: (If you ever switch) Use the native 
ADMIN SET AUTOMATED CLUSTER SNAPSHOT ON
. References • administration/cluster_snapshot.md • administration/Meta_recovery.md • administration/Backup_and_restore.md References • administration/Meta_recovery.md • quick_start/helm.md
To enable FQDN (Fully Qualified Domain Name) access in the StarRocks Helm chart, you need to set the 
enableFQDN
property to 
true
. This configuration tells the StarRocks Operator to start the Frontends (FE) with the 
--host_type FQDN
flag and ensures that Backends (BE) and Compute Nodes (CN) are registered using their Kubernetes DNS names rather than internal IP addresses. 1. Configuration in 
values.yaml
 In the kube-starrocks Helm chart (which includes both the operator and the cluster), add the following to your `values.yaml`:
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yaml
starrocks:
  starrocksCluster:
    enableFQDN: true
If you are using the starrocks (cluster-only) chart or editing the 
StarRocksCluster
Custom Resource (CR) directly:
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yaml
spec:
  enableFQDN: true
2. What this changes * Startup Flag: The operator automatically adds 
--host_type FQDN
to the FE startup command. * Node Registration: When BEs or CNs join the cluster, they will use their stable network identity (e.g., 
starrocks-be-0.starrocks-be-search.svc.cluster.local
) instead of an ephemeral Pod IP. * Metadata: The FE metadata will store hostnames instead of IPs, making the cluster resilient to Pod restarts or IP changes. 3. Important Considerations * Version Requirement: FQDN support requires StarRocks version 2.4.0 or later and StarRocks Operator version 1.5.0 or later. * Priority Networks: If you previously configured 
priority_networks
in your 
fe.conf
or 
be.conf
, you should generally remove or comment out that setting when 
enableFQDN
is true. FQDN mode bypasses the need for IP-based network matching. * Existing Clusters: If you are enabling FQDN on an existing cluster that was started in IP mode, you must perform a manual migration of the metadata using SQL commands (e.g., 
ALTER SYSTEM MODIFY FRONTEND HOST...
) because the FEs will not be able to recognize their old IP-based identities once restarted in FQDN mode. For a fresh installation via Helm, simply setting the flag is sufficient. 4. Verification After the pods are running, log into StarRocks via MySQL and check the hostnames:
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sql
-- Check FEs
SHOW PROC '/frontends';

-- Check BEs
SHOW PROC '/backends';
The 
Host
or 
IP
columns should show the Kubernetes service domain names instead of numeric IP addresses. References • administration/management/enable_fqdn.md • deployment/environment_configurations.md • faq/operation_maintenance_faq.md
m
@Rocky So for a disaster recovery plan in shared-nothing, we should run a sidecar container or velero for metadata packaup, and manually run backup command for specific table, db, materials view.... and then restore it for data backup. Right?
r
Yes, your understanding is correct. For a shared-nothing architecture, a complete Disaster Recovery (DR) plan requires two separate layers because the 
BACKUP
command does not capture the entire state of the cluster. 1. Metadata Layer (Global State) The 
BACKUP
command cannot back up global metadata such as users, roles, privileges, resource groups, or cluster configurations. * Method: Use Velero (to snapshot FE Persistent Volumes) or a Sidecar (to sync the 
meta/image
directory to S3). * Why: If you lose your FE metadata, you lose your security settings and the "map" of where data is stored on the BEs. 2. Data Layer (Tables & MVs) The 
BACKUP
command is used to create a point-in-time snapshot of the actual data stored on the Backends (BE). * Command: 
BACKUP DATABASE <db_name> SNAPSHOT <label> TO <repository> ...
* Scope (v3.4+): It now supports tables, partitions, logical views, and UDFs. * Materialized Views: * Synchronous MVs: Automatically backed up when you back up the base table. * Asynchronous MVs: Supported since v3.2, but you must ensure the FE config 
enable_backup_materialized_view
is set to 
true
. * Restore: Use the 
RESTORE
command on the target cluster. You do not need to create the table schema beforehand; the restore process handles it. ────────── Comparison of DR Strategies for Shared-Nothing Strategy | Automation Level | Recovery Point Objective (RPO) | Scope Velero / CSI Snapshots | High | Depends on snapshot frequency | Full Cluster. Backs up FE meta and BE data volumes. Best for K8s. Meta Sync + BACKUP | Medium (Manual/Scripted) | High (Manual backups take time) | Data + Schema. Misses users/roles unless you sync the FE meta directory separately. Cross-Cluster Replication (CCR) | Highest | Near Zero | Automated. Continuously syncs data and metadata to a standby cluster. Recommendation for your Plan If you are on Kubernetes and your storage supports it, Velero with CSI snapshots is the most robust path because it handles both FE and BE volumes in one workflow. If you proceed with your manual/sidecar plan: 1. Automate Metadata: Use a sidecar to sync the FE 
meta
folder. 2. Automate Data: Use a K8s 
CronJob
to call a script that executes the 
BACKUP
SQL command. 3. Config Check: If using Asynchronous MVs, set 
ADMIN SET FRONTEND CONFIG ("enable_backup_materialized_view" = "true");
. References • administration/management/Backup_and_restore.md • administration/management/FE_configuration.md • administration/Meta_recovery.md • sql-reference/sql-statements/backup_restore/BACKUP.md References • administration/management/resource_management/Replica.md • administration/cluster_snapshot.md • introduction/Architecture.md
m
@Rocky Run a script to backupt metadata every 6 hours and push it to a minio s3
r
To automate the backup of StarRocks FE metadata to MinIO, you should use a Sidecar container approach. This is the most reliable method in Kubernetes because the sidecar has direct access to the FE's metadata volume (
meta_dir
), which is typically a 
ReadWriteOnce
Persistent Volume that cannot be mounted by other pods (like a standard CronJob) while the FE is running. 1. The Strategy 1. Trigger Snapshot: Run 
ALTER SYSTEM CREATE IMAGE
via a SQL client to force the Leader FE to write the latest metadata to disk. 2. Wait: Since the command is asynchronous, the script waits for the 
image.<id>
file to be generated. 3. Sync to MinIO: Use the 
mc
(MinIO Client) or 
aws-cli
to sync the 
/opt/starrocks/fe/meta
directory to your S3 bucket. 2. Sidecar Configuration (YAML) Add this to your 
StarRocksCluster
CRD under 
spec.starRocksFeSpec
. This example uses a lightweight image with 
mysql-client
and 
aws-cli
(MinIO is S3-compatible).
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yaml
spec:
  starRocksFeSpec:
    sidecarContainers:
      - name: metadata-backup
        image: amazon/aws-cli # Includes aws-cli; you can also use a custom image with 'mc'
        env:
          - name: AWS_ACCESS_KEY_ID
            value: "your-minio-access-key"
          - name: AWS_SECRET_ACCESS_KEY
            value: "your-minio-secret-key"
          - name: MINIO_ENDPOINT
            value: "<http://minio-service.minio-namespace.svc.cluster.local:9000>"
          - name: FE_QUERY_PORT
            value: "9030"
        command: ["/bin/sh", "-c"]
        args:
          - |
            while true; do
              echo "Starting metadata backup..."
              # 1. Trigger the image creation (User 'root' with no password example)
              # Note: Use a secret for the password in production!
              aws s3 --endpoint-url $MINIO_ENDPOINT s3 ls || echo "MinIO connection check failed"
              
              # Execute SQL to create image
              # We use 127.0.0.1 because the sidecar shares the network with the FE container
              mysql -h 127.0.0.1 -P $FE_QUERY_PORT -u root -e "ALTER SYSTEM CREATE IMAGE;"
              
              echo "Waiting 5 minutes for image to be created..."
              sleep 300
              
              # 2. Sync the meta directory to MinIO
              # Only sync the 'image' and 'bdb' subdirectories which contain the actual state
              aws s3 sync /opt/starrocks/fe/meta <s3://my-backup-bucket/fe-metadata/$(hostname)/> \
                --endpoint-url $MINIO_ENDPOINT \
                --exclude "fe.log*" \
                --no-verify-ssl
              
              echo "Backup completed. Sleeping for 6 hours..."
              sleep 21600 # 6 hours
            done
        volumeMounts:
          - name: fe-meta
            mountPath: /opt/starrocks/fe/meta
3. Key Script Details * Targeting the Leader: 
ALTER SYSTEM CREATE IMAGE
only works on the Leader FE. In a multi-FE setup, the script will run on all FEs. On non-leader FEs, the SQL command will fail or be forwarded, but the 
aws s3 sync
will still safely back up the local metadata copy (which is synchronized via BDB JE). * Directory Path: The 
meta_dir
defaults to 
/opt/starrocks/fe/meta
. Ensure the 
volumeMounts.name
matches the name of the metadata volume defined in your FE spec (usually 
fe-meta
). * Wait Time: Image creation time depends on the size of your metadata. For most clusters, 5 minutes is sufficient. You can refine this by checking for file timestamps if needed. 4. Recovery If you need to restore from this backup: 1. Download the 
meta
folder from MinIO. 2. Place it in the 
meta_dir
of a fresh FE. 3. Start the FE with the 
metadata_enable_recovery_mode = true
flag in 
fe.conf
(if the BDB JE logs are fragmented) or simply as a new cluster seed. Alternative: Kubernetes CronJob
If you prefer not to have a long-running sidecar, you can use a 
CronJob
that uses 
kubectl exec
to perform the same steps: 1. 
kubectl exec <leader-fe-pod> -- mysql -e "ALTER SYSTEM CREATE IMAGE;"
2. 
kubectl exec <leader-fe-pod> -- mc mirror /opt/starrocks/fe/meta minio/backups
Note: This requires the FE image to have 
mc
or 
aws-cli
installed, or for you to install it at runtime. References • administration/management/FE_configuration.md • administration/Meta_recovery.md • introduction/Architecture.md • quick_start/shared-nothing.md
m
@Rocky does each Fe have its own meta file?
r
Yes, each FE (Front End) maintains its own local copy of the metadata in its respective 
meta_dir
(defaulting to 
/opt/starrocks/fe/meta
). Here is how it works in a multi-FE setup: 1. Local Storage for Each Pod In a Kubernetes deployment, each FE Pod has its own Persistent Volume (PV). Inside that PV, you will find: * 
image/
directory: Contains the full snapshot of the metadata (the "Image"). * 
bdb/
directory: Contains the Berkeley DB (BDB JE) edit logs. These are the incremental changes made since the last image was created. 2. How they stay in sync StarRocks uses a Leader-Follower architecture to keep these local files identical: * Leader FE: All metadata changes (like creating a table or adding a user) are first written to the Leader's local BDB logs. * Follower FEs: They continuously pull these edit logs from the Leader and apply them to their own local metadata files. * Checkpointing: Periodically, the Leader FE converts the incremental logs into a new 
image
file and pushes it to the Followers so they can prune their old log files. 3. Why this matters for your DR plan Because each FE has its own copy: * High Availability: If the Leader FE Pod dies, a Follower already has a nearly identical copy of the metadata and can be elected as the new Leader immediately. * Backup Strategy: In your sidecar script, you technically only need to back up the metadata from the Leader FE because it is the "source of truth." However, since any Follower can become a Leader, backing up from the current Leader (or all of them) ensures you always have the most recent state. * Consistency: When you run 
ALTER SYSTEM CREATE IMAGE;
, it tells the Leader to consolidate its logs into a single image file, which then gets synced to all other FEs. Summary: They do not share a single metadata file; they keep individual copies in sync via the network. This is why you must ensure each FE Pod in your Helm chart has its own Persistent Volume Claim (PVC). References • administration/Meta_recovery.md • introduction/Architecture.md • administration/management/FE_configuration.md • faq/operation_maintenance_faq.md References • administration/management/FE_configuration.md • faq/operation_maintenance_faq.md • administration/Meta_recovery.md
Yes, each FE node maintains its own complete and independent copy of the metadata in its local storage (defined by 
meta_dir
). While they are separate files on disk, they are kept synchronized to be identical via the following mechanism: 1. Independent Storage In a Kubernetes or distributed environment, every FE pod has its own local directory (usually a Persistent Volume). Inside this directory (
/opt/starrocks/fe/meta
), you will find: * 
image/
: A point-in-time snapshot of the entire cluster's metadata. * 
bdb/
: The Berkeley DB (BDB JE) logs that record every incremental change (e.g., "Create Table", "Add User") since the last image was created. 2. How Synchronization Works StarRocks uses a Leader-Follower consensus (based on the Raft protocol) to ensure these separate files stay consistent: * Leader FE: The only node that can write to the metadata. When you run a command like 
CREATE TABLE
, the Leader writes it to its local BDB log first. * Follower FEs: They constantly pull new log entries from the Leader and apply them to their own local metadata files. * Image Checkpointing: Periodically (or manually via 
ALTER SYSTEM CREATE IMAGE
), the Leader merges its logs into a new 
image
file and distributes it to the Followers so they can clean up their old log files. 3. Why this is important for your DR Plan * Redundancy: If one FE node's disk fails, the other FEs still have the full metadata. * Backups: You only need to back up the 
meta
directory from one healthy FE (preferably the Leader) to have a complete backup of the cluster's state. * Recovery: If you lose the entire cluster, you can point a new FE to a restored copy of this 
meta
directory, and it will be able to reconstruct the entire cluster state (users, permissions, table schemas, etc.). Summary: Each FE has its own physical metadata files, but the content of those files is synchronized across all FEs to ensure they are logically identical. References • introduction/Architecture.md • administration/Meta_recovery.md • administration/management/FE_configuration.md • faq/operation_maintenance_faq.md References • faq/operation_maintenance_faq.md • administration/management/FE_configuration.md • administration/Meta_recovery.md • introduction/Architecture.md
m
@Rocky Do we need to take a snapshot from Be's meta files?
r
In general, no, you do not need to manually back up or snapshot the BE (Backend) metadata files in the same way you do for the FE. Here is the breakdown of why BE metadata is treated differently: 1. Metadata vs. Data * FE Metadata (The Brain): Contains the cluster's logical state (table schemas, user permissions, tablet locations). If this is lost and you have no backup, the entire cluster is gone. * BE Metadata (The Local Map): Contains local information about which tablets are stored on that specific BE. This information is redundant because the FE already knows where every tablet is located across the cluster. 2. High Availability (Shared-Nothing) In a standard StarRocks cluster (Shared-Nothing), data is typically stored with 3 replicas. * If a BE's metadata or disk is lost, the FE will notice the replicas are missing. * The FE will then instruct other healthy BEs to create new replicas to restore the count to 3. * Result: The BE is "disposable." You can replace a failed BE with a fresh one, and the cluster will automatically re-balance and re-replicate data to it. 3. Shared-Data Mode (Cloud Native) If you are using the Shared-Data architecture: * The actual data and metadata are stored in Object Storage (like S3/MinIO). * The BEs (or CNs) are effectively stateless workers. There is no critical local metadata to back up because the "source of truth" is already in the S3 bucket. 4. How to correctly back up BE Data If your goal is to protect the data (not just the metadata), you should not copy files from the BE's 
/storage
directory. Instead, use the StarRocks native backup feature:
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sql
-- This backs up both the FE metadata and the actual data from the BEs 
-- for a specific database/table and pushes it to your S3/MinIO.
BACKUP SNAPSHOT demo_db.snapshot_label
TO YOUR_S3_REPOSITORY
ON (table_name);
Summary Component | Backup Necessity | Method FE Metadata | Critical | 
ALTER SYSTEM CREATE IMAGE
+ Sync 
meta/
dir. BE Metadata | Not Required | Automatically managed and synced by FE. BE Data | High | Use 
BACKUP
statement or rely on 3x replicas. Bottom line: Focus your automated scripts on the FE metadata (as you've already started) and use the SQL 
BACKUP
 command for long-term data retention of your actual tables. References • administration/cluster_snapshot.md • administration/Meta_recovery.md • faq/operation_maintenance_faq.md • administration/management/BE_configuration.md References • administration/Meta_recovery.md
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