Cassandra 備份與復原

本節將說明如何為在 Apigee 混合式執行階段平面中安裝的 Apache Cassandra 資料庫環,設定資料備份和復原功能。另請參閱 Cassandra 資料庫

關於 Cassandra 備份的注意事項

Cassandra 是複製資料庫,可在每個區域或資料中心中至少複製 3 份資料。Cassandra 會使用串流複寫和讀取修復功能,在任何時間點維護各個區域或資料中心的資料副本。

在混合式架構中,Cassandra 備份預設為「未啟用」。不過,建議您啟用 Cassandra 備份功能,以防資料意外刪除。

系統會備份哪些內容?

本主題所述的備份設定會備份下列實體:

  • Cassandra 結構定義,包括使用者結構定義 (Apigee 鍵值空間定義)
  • 每個節點的 Cassandra 分區符記資訊
  • Cassandra 資料的快照

備份資料儲存在何處?

備份資料會儲存在您必須建立的 Google Cloud Storage (GCS) 值區中。本主題將說明如何建立及設定 bucket。

排定 Cassandra 備份時間

備份作業會在執行時間平面中排定為 Cron 工作。如要排定 Cassandra 備份作業時間,請按照下列步驟操作:

  1. 執行下列 create-service-account 指令,建立具有標準 roles/storage.objectAdmin 角色的 GCP 服務帳戶 (SA)。這個 SA 角色可讓您將備份資料寫入 Google Cloud Storage (GCS)。在混合式安裝根目錄中執行下列指令:
    ./tools/create-service-account apigee-cassandra output-dir
    例如:
    ./tools/create-service-account apigee-cassandra ./service-accounts
    如要進一步瞭解 GCP 服務帳戶,請參閱「建立及管理服務帳戶」一文。
  2. create-service-account 指令會儲存含有服務帳戶私密金鑰的 JSON 檔案。檔案會儲存在執行指令所在的目錄中。您將在後續步驟中需要這個檔案的路徑。
  3. 建立 GCS 值區。 為值區指定合理的資料保留政策。Apigee 建議的資料保留政策為 15 天。
  4. 開啟 overrides.yaml 檔案。
  5. 新增下列 cassandra.backup 屬性即可啟用備份功能。請勿移除任何已設定的屬性。
    cassandra:
      ...
    
      backup:
        enabled: true
        serviceAccountPath: sa_json_file_path
        dbStorageBucket: gcs_bucket_path
        schedule: backup_schedule_code
    
      ...
    其中:
    屬性 說明
    enabled 備份功能預設為停用。您必須將這項屬性設為 true
    serviceAccountPath 您在執行 ./tools/create-service-account 時下載的服務帳戶 JSON 檔案在檔案系統中的路徑
    dbStorageBucket GCS 儲存空間值區路徑的格式為 gs://bucket_name。必須使用 gs://
    schedule 備份作業開始的時間,以 標準 crontab 語法指定。預設值:0 2 * * *

    注意:請勿在將備份設定套用至叢集後不久,就排定備份作業。套用備份設定後,Kubernetes 會重新建立 Cassandra 節點。如果備份作業在節點重新啟動前開始 (可能需要幾分鐘),備份作業就會失敗。

    例如:
    ...
    
    cassandra:
      storage:
        type: gcepd
        capacity: 50Gi
        gcepd:
          replicationType: regional-pd
      sslRootCAPath: "/Users/myhome/ssh/cassandra.crt"
      sslCertPath: "/Users/myhome/ssh/cassandra.crt"
      sslKeyPath: "/Users/myhome/ssh/cassandra.key"
      auth:
        default:
          password: "abc123"
        admin:
          password: "abc234"
        ddl:
          password: "abc345"
        dml:
          password: "abc456"
      nodeSelector:
        key: cloud.google.com/gke-nodepool
        value: apigee-data
      backup:
        enabled: true
        serviceAccountPath: "/Users/myhome/.ssh/my_cassandra_backup.json"
        dbStorageBucket: "gs://myname-cassandra-backup"
        schedule: "45 23 * * 6"
    
      ... 
  6. 將設定變更套用至新叢集。例如:
    ./apigeectl apply -c cassandra -f my-overrides.yaml

還原備份

還原作業會從備份位置取得資料,並將資料還原至具有相同 Pod 數量的新 Cassandra 叢集。新叢集的命名空間必須與執行階段平面叢集不同。

如要還原 Cassandra 備份,請按照下列步驟操作:

  1. 使用新的命名空間建立新的 Kubernetes 叢集。您無法使用原始混合安裝作業所用的叢集/命名空間。
  2. 在根混合安裝目錄中,建立新的 overrides-restore.yaml 檔案。
  3. 將完整的 Cassandra 設定從原始 overrides.yaml 檔案複製到新檔案。
  4. 新增命名空間元素。請勿使用原始叢集的命名空間。
  5. namespace: your-restore-namespace
    
    cassandra:
      storage:
        type: gcepd
        capacity: 50Gi
        gcepd:
          replicationType: regional-pd
      nodeSelector:
        key: cloud.google.com/gke-nodepool
        value: apigee-data
      sslRootCAPath: path_to_root_ca_file
      sslCertPath: path_to_ssl_cert_file
      sslKeyPath: path_to_ssl_key_file
      auth:
        default:
          password: your_cassandra_password
        admin:
          password: admin_password
        ddl:
          password: ddl_password
        dml:
          password: dml_password
    
      restore:
          enabled: true
          snapshotTimestamp: timestamp
          serviceAccountPath: sa_json_file_path
          dbStorageBucket: gcs_bucket_path
          image:
            pullPolicy: Always
    其中:
    屬性 說明
    ssl*Pathauth.* 使用建立原始 Cassandra 資料庫時使用的 TLS 驗證憑證
    snapshotTimestamp 要還原的備份快照時間戳記。
    serviceAccountPath 您為備份作業建立的服務帳戶在檔案系統中的路徑。
    dbStorageBucket 備份儲存位置的 GCS 儲存值區路徑,格式如下:gs://bucket_name。必須使用 gs://
    例如:
    namespace: cassandra-restore
    
    cassandra:
      storage:
        type: gcepd
        capacity: 50Gi
        gcepd:
          replicationType: regional-pd
      sslRootCAPath: "/Users/myhome/ssh/cassandra.crt"
      sslCertPath: "/Users/myhome/ssh/cassandra.crt"
      sslKeyPath: "/Users/myhome/ssh/cassandra.key"
      auth:
        default:
          password: "abc123"
        admin:
          password: "abc234"
        ddl:
          password: "abc345"
        dml:
          password: "abc456"
      nodeSelector:
        key: cloud.google.com/gke-nodepool
        value: apigee-data
      restore:
        enabled: true
        snapshotTimestamp: "20190417002207"
        serviceAccountPath: "/Users/myhome/.ssh/my_cassandra_backup.json"
        dbStorageBucket: "gs://myname-cassandra-backup"
        image:
          pullPolicy: Always

    其中 snapshotTimestamp 是與要還原的備份相關聯的時間戳記。

  6. 建立新的 Cassandra 叢集:
      ./apigeectl apply -c cassandra -f ./overrides-restore.yaml

查看還原記錄

您可以檢查還原工作記錄,並使用 grep 搜尋 error,確認還原記錄沒有錯誤。

確認還原作業已完成

如要確認還原作業是否已完成,請按照下列步驟操作:

kubectl get pods

NAME                           READY     STATUS      RESTARTS   AGE
apigee-cassandra-0             1/1       Running     0          1h
apigee-cassandra-1             1/1       Running     0          1h
apigee-cassandra-2             1/1       Running     0          59m
apigee-cassandra-restore-b4lgf 0/1       Completed   0          51m

查看還原記錄檔

如要查看還原記錄,請按照下列步驟操作:

kubectl logs -f apigee-cassandra-restore-b4lgf

Restore Logs:

Activated service account credentials for: [apigee-cassandra-backup-svc@gce-myusername.iam.gserviceaccount.com]
to download file gs://gce-myusername-apigee-cassandra-backup/apigeecluster/dc-1/backup_20190405011309_schema.tgz
INFO: download sucessfully extracted the backup files from gs://gce-myusername-apigee-cassandra-backup/apigeecluster/dc-1
finished downloading schema.cql
to create schema from 10.32.0.28

Warnings :
dclocal_read_repair_chance table option has been deprecated and will be removed in version 4.0

dclocal_read_repair_chance table option has been deprecated and will be removed in version 4.0


Warnings :
dclocal_read_repair_chance table option has been deprecated and will be removed in version 4.0

dclocal_read_repair_chance table option has been deprecated and will be removed in version 4.0

INFO: the schema has been restored
starting apigee-cassandra-0 in default
starting apigee-cassandra-1 in default
starting apigee-cassandra-2 in default
84 95 106
waiting on waiting nodes $pid to finish  84
Activated service account credentials for: [apigee-cassandra-backup-svc@gce-myusername.iam.gserviceaccount.com]
Activated service account credentials for: [apigee-cassandra-backup-svc@gce-myusername.iam.gserviceaccount.com]
Activated service account credentials for: [apigee-cassandra-backup-svc@gce-myusername.iam.gserviceaccount.com]
INFO: restore downloaded  tarball and extracted the file from  gs://gce-myusername-apigee-cassandra-backup/apigeecluster/dc-1
INFO: restore downloaded  tarball and extracted the file from  gs://gce-myusername-apigee-cassandra-backup/apigeecluster/dc-1
INFO: restore downloaded  tarball and extracted the file from  gs://gce-myusername-apigee-cassandra-backup/apigeecluster/dc-1
INFO  12:02:28 Configuration location: file:/etc/cassandra/cassandra.yaml
…...

INFO  12:02:41 [Stream #e013ee80-5863-11e9-8458-353e9e3cb7f9] All sessions completed

Summary statistics:
   Connections per host    : 3
   Total files transferred : 2
   Total bytes transferred : 0.378KiB
   Total duration          : 5048 ms
   Average transfer rate   : 0.074KiB/s
   Peak transfer rate      : 0.075KiB/s

progress: [/10.32.1.155]0:1/1 100% 1:1/1 100% [/10.32.0.28]1:1/1 100% 0:1/1 100% [/10.32.3.220]0:1/1 100% 1:1/1 100% total: 100% 0.000KiB/s (avg: 0.074KiB/s)
INFO  12:02:41 [Stream #e013ee80-5863-11e9-8458-353e9e3cb7f9] All sessions completed
progress: [/10.32.1.155]0:1/1 100% 1:1/1 100% [/10.32.0.28]1:1/1 100% 0:1/1 100% [/10.32.3.220]0:1/1 100% 1:1/1 100% total: 100% 0.000KiB/s (avg: 0.074KiB/s)
INFO  12:02:41 [Stream #e013ee80-5863-11e9-8458-353e9e3cb7f9] All sessions completed
INFO  12:02:41 [Stream #e013ee80-5863-11e9-8458-353e9e3cb7f9] All sessions completed
INFO: ./apigee/data/cassandra/data/ks1/user-9fbae960571411e99652c7b15b2db6cc restored successfully
INFO: Restore 20190405011309 completed
INFO: ./apigee/data/cassandra/data/ks1/user-9fbae960571411e99652c7b15b2db6cc restored successfully
INFO: Restore 20190405011309 completed
waiting on waiting nodes $pid to finish  106
Restore finished

驗證備份工作

您也可以在安排備份 Cron 工作後驗證備份工作。排定 cron 工作後,您應該會看到類似下方的內容:

kubectl get pods
NAME                        READY     STATUS      RESTARTS   AGE
apigee-cassandra-0          1/1       Running     0          2h
apigee-cassandra-1          1/1       Running     0          2h
apigee-cassandra-2          1/1       Running     0          2h
apigee-cassandra-backup-1554515580-pff6s   0/1       Running     0          54s

檢查備份記錄

備份工作:

  • 建立 schema.cql 檔案。
  • 將其上傳至儲存體值區。
  • 會回應節點,同時備份及上傳資料。
  • 等待所有資料上傳完畢。
kubectl logs -f apigee-cassandra-backup-1554515580-pff6s

myusername-macbookpro:cassandra-backup-utility myusername$ kubectl logs -f apigee-cassandra-backup-1554577680-f9sc4
starting apigee-cassandra-0 in default
starting apigee-cassandra-1 in default
starting apigee-cassandra-2 in default
35 46 57
waiting on process  35
Activated service account credentials for: [apigee-cassandra-backup-svc@gce-myusername.iam.gserviceaccount.com]
Activated service account credentials for: [apigee-cassandra-backup-svc@gce-myusername.iam.gserviceaccount.com]
Activated service account credentials for: [apigee-cassandra-backup-svc@gce-myusername.iam.gserviceaccount.com]
Requested creating snapshot(s) for [all keyspaces] with snapshot name [20190406190808] and options {skipFlush=false}
Snapshot directory: 20190406190808
INFO: backup created cassandra snapshot 20190406190808
tar: Removing leading `/' from member names
/apigee/data/cassandra/data/ks1/mytest3-37bc2df0587811e98e8d875b0ed64754/snapshots/
/apigee/data/cassandra/data/ks1/mytest3-37bc2df0587811e98e8d875b0ed64754/snapshots/20190406190808/
/apigee/data/cassandra/data/ks1/mytest3-37bc2df0587811e98e8d875b0ed64754/snapshots/20190406190808/mc-1-big-Data.db
Requested creating snapshot(s) for [all keyspaces] with snapshot name [20190406190808] and options {skipFlush=false}
Requested creating snapshot(s) for [all keyspaces] with snapshot name [20190406190808] and options {skipFlush=false}
Snapshot directory: 20190406190808
INFO: backup created cassandra snapshot 20190406190808
tar: Removing leading `/' from member names
/apigee/data/cassandra/data/system/hints-2666e20573ef38b390fefecf96e8f0c7/snapshots/
/apigee/data/cassandra/data/system/hints-2666e20573ef38b390fefecf96e8f0c7/snapshots/20190406190808/
/apigee/data/cassandra/data/system/hints-2666e20573ef38b390fefecf96e8f0c7/snapshots/20190406190808/manifest.json
/apigee/data/cassandra/data/system/prepared_statements-18a9c2576a0c3841ba718cd529849fef/snapshots/
/apigee/data/cassandra/data/system/prepared_statements-18a9c2576a0c3841ba718cd529849fef/snapshots/20190406190808/
/apigee/data/cassandra/data/system/prepared_statements-18a9c2576a0c3841ba718cd529849fef/snapshots/20190406190808/manifest.json
/apigee/data/cassandra/data/system/range_xfers-55d764384e553f8b9f6e676d4af3976d/snapshots/
/apigee/data/cassandra/data/system/range_xfers-55d764384e553f8b9f6e676d4af3976d/snapshots/20190406190808/
/apigee/data/cassandra/data/system/range_xfers-55d764384e553f8b9f6e676d4af3976d/snapshots/20190406190808/manifest.json
/apigee/data/cassandra/data/system/peer_events-59dfeaea8db2334191ef109974d81484/snapshots/
/apigee/data/cassandra/data/system/peer_events-59dfeaea8db2334191ef109974d81484/snapshots/20190406190808/
/apigee/data/cassandra/data/system/peer_events-59dfeaea8db2334191ef109974d81484/snapshots/20190406190808/manifest.json
/apigee/data/cassandra/data/system/built_views-4b3c50a9ea873d7691016dbc9c38494a/snapshots/
/apigee/data/cassandra/data/system/built_views-4b3c50a9ea873d7691016dbc9c38494a/snapshots/20190406190808/
/apigee/data/cassandra/data/system/built_views-4b3c50a9ea873d7691016dbc9c38494a/snapshots/20190406190808/manifest.json
……
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-3-big-Filter.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-2-big-CompressionInfo.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-2-big-Index.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-3-big-Statistics.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-2-big-Data.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-1-big-Index.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-1-big-Statistics.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-2-big-TOC.txt
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-2-big-Statistics.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-1-big-Summary.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-1-big-Filter.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-2-big-Summary.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-3-big-Index.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/manifest.json
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-2-big-Filter.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-2-big-Digest.crc32
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-3-big-Summary.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-3-big-Data.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-1-big-TOC.txt
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/schema.cql
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-3-big-CompressionInfo.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-1-big-Digest.crc32
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-3-big-TOC.txt
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-1-big-Data.db
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-3-big-Digest.crc32
/apigee/data/cassandra/data/ks2/user-d6d39d70586311e98e8d875b0ed64754/snapshots/20190406190808/mc-1-big-CompressionInfo.db
……
/tmp/tokens.txt
/ [1 files][    0.0 B/    0.0 B]
Operation completed over 1 objects.
/ [1 files][    0.0 B/    0.0 B]
Operation completed over 1 objects.
INFO: backup created tarball and transfered the file to gs://gce-myusername-apigee-cassandra-backup/apigeecluster/dc-1
INFO: removing cassandra snapshot
INFO: backup created tarball and transfered the file to gs://gce-myusername-apigee-cassandra-backup/apigeecluster/dc-1
INFO: removing cassandra snapshot
Requested clearing snapshot(s) for [all keyspaces]
INFO: Backup 20190406190808 completed
waiting on process  46
Requested clearing snapshot(s) for [all keyspaces]
INFO: Backup 20190406190808 completed
Requested clearing snapshot(s) for [all keyspaces]
waiting on process  57
INFO: Backup 20190406190808 completed
waiting result
to get schema from 10.32.0.28
INFO: /tmp/schema.cql has been generated
Activated service account credentials for: [apigee-cassandra-backup-svc@gce-myusername.iam.gserviceaccount.com]
tar: removing leading '/' from member names
tmp/schema.cql
Copying from ...
/ [1 files][    0.0 B/    0.0 B]
Operation completed over 1 objects.
INFO: backup created tarball and transfered the file to gs://gce-myusername-apigee-cassandra-backup/apigeecluster/dc-1
finished uploading schema.cql