如何恢复Cassandra快照？

我正在为Cassandra数据库构建一个备份和恢复过程，以便在需要时随时准备就绪，并了解详细信息，以便构建适合生产的产品。我遵循税务局的指示：

首先，我将在一个dev box上植入数据库，然后尝试使备份/恢复工作。以下是备份脚本：

#!/bin/bash

cd /opt/apache-cassandra-2.0.9
./bin/nodetool clearsnapshot -t after_seeding makeyourcase
./bin/nodetool snapshot -t after_seeding makeyourcase

cd /var/lib/
tar czf after_seeding.tgz cassandra/data/makeyourcase/*/snapshots/after_seeding

是的，焦油也许不是最有效的方法，但我现在只是想让它起作用。我查过焦油，所有的文件都在那里

备份数据库后，我关闭Cassandra和我的应用程序，然后

rm-rf/var/lib/Cassandra/

模拟完全丢失

现在恢复数据库。从中恢复“方法2”比方法1更兼容我的架构创建组件

因此，方法2/步骤1，“重新创建模式”：重启Cassandra，然后重启我的应用程序。该应用程序用于在必要时在启动时重新创建架构。一旦启动，就会有一个工作的Cassandra节点，其中包含应用程序的模式，但没有数据

方法2/步骤2“恢复快照”：他们给出了三种选择，第一种是使用sstableloader，记录在。加载程序所需的文件夹结构与快照工具创建的文件夹结构完全不同，因此所有内容都必须移动到位。在遇到这些麻烦之前，我先在一张桌子上试试：

>./bin/sstableloader makeyourcase/users
Error: Could not find or load main class org.apache.cassandra.tools.BulkLoader

嗯，那是行不通的。BulkLoader位于./lib/apache-cassandra-2.0.9.jar中，但似乎没有对其进行开箱即用的设置。与其调试该工具，不如转到第二个备选方案，将快照目录复制到makeyourcase/users/snapshots/目录中。这应该很容易，因为我们正在将快照目录扔回它的来源，所以

tar xzf after_seeding.tgz

应该做到以下几点：

cd /var/lib/
tar xzf after_seeding.tgz
chmod -R u+rwx cassandra/data/makeyourcase

这会将快照目录放回各自的“快照”目录下，刷新会恢复数据：

cd /opt/apache-cassandra-2.0.9
./bin/nodetool refresh -- makeyourcase users

这是毫无怨言的。请注意，您必须为每个表运行此操作，因此必须首先生成表列表。但是，在我们这样做之前，请注意卡桑德拉日志中有一些有趣的东西：

INFO 14:32:26,319 Loading new SSTables for makeyourcase/users...
INFO 14:32:26,326 No new SSTables were found for makeyourcase/users

我们把快照放回去了，但是卡桑德拉没有找到。我还尝试将快照目录移动到现有SSTables目录下，并将旧的SSTable文件复制到现有目录中，但日志中出现了相同的错误。卡桑德拉没有记录它希望在哪里找到它们，只是它找不到它们。文档说要将它们放入名为data/keyspace/table_name-UUID的目录中，但没有这样的目录。有一个名为data/makeyourcase/users/snapshots/1408820504987 users/，但将snapshot dir或单个文件放在那里不起作用

第三种选择，“节点重启方法”看起来不适合多节点生产环境，所以我没有尝试过

编辑：

为了让下一个人完全明白这一点，下面是应用公认答案的初步、有效的备份和恢复脚本

myc_backup.sh：

#!/bin/bash

cd ~/bootstrap/apache-cassandra-2.0.9
./bin/nodetool clearsnapshot -t after_seeding makeyourcase
./bin/nodetool snapshot -t after_seeding makeyourcase

cd /var/lib/
tar czf after_seeding.tgz cassandra/data/makeyourcase/*/snapshots/after_seeding

myc_restore.sh：

#!/bin/bash

cd /var/lib/
tar xzf after_seeding.tgz
chmod -R u+rwx cassandra/data/makeyourcase

cd ~/bootstrap/apache-cassandra-2.0.9
TABLE_LIST=`./bin/nodetool cfstats makeyourcase | grep "Table: " | sed -e 's+^.*: ++'`
for TABLE in $TABLE_LIST; do
    echo "Restore table ${TABLE}"
    cd /var/lib/cassandra/data/makeyourcase/${TABLE}
    if [ -d "snapshots/after_seeding" ]; then
        cp snapshots/after_seeding/* .
        cd ~/bootstrap/apache-cassandra-2.0.9
        ./bin/nodetool refresh -- makeyourcase ${TABLE}
        cd /var/lib/cassandra/data/makeyourcase/${TABLE}
        rm -rf snapshots/after_seeding
        echo "    Table ${TABLE} restored."
    else
        echo "    >>> Nothing to restore."
    fi
done

添加了更多详细信息：

---

您可以使用以下方法为特定密钥空间运行快照：

$ nodetool snapshot <mykeyspace> -t <SnapshotDirectoryName>

准备好恢复后，将快照数据复制回keyspace/table目录（每个表一个）：

$pwd
/var/lib/cassandra/data/mykeyspace/mytable
$sudo cp快照//*。

你提到：

这会将快照目录放回各自的“快照”目录下，刷新>会还原数据：

cd /opt/apache-cassandra-2.0.9
./bin/nodetool refresh -- makeyourcase users

我认为问题在于您正在将快照数据恢复到快照目录中。它应该在表目录中。其他一切似乎都是对的，让我知道

文档说把它们放到一个名为 data/keyspace/table_name-UUID，但没有这样的目录

---

您没有这个UUID目录，因为您使用的是cassandra 2.0，而这个UUID是从cassandra 2.2开始的。步骤1：我使用下面的命令创建了一个表

CREATE TABLE Cricket (
    PlayerID uuid,
    LastName varchar,
    FirstName varchar,  
    City varchar,
    State varchar,
    PRIMARY KEY (PlayerID));

INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Pendulkar', 'Sachin', 'Mumbai','Maharastra');
INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Vholi', 'Virat', 'Delhi','New Delhi');
INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Sharma', 'Rohit', 'Berhampur','Odisha');

cassandra@node1:~$ sstableloader -d 10.213.61.21 -username cassandra --password cassandra /home/cassandra/data/students_details/cricket-d3576f60960f11ea947b39646348bb4f/snapshots
    Established connection to initial hosts
    Opening sstables and calculating sections to stream

    Summary statistics:
       Connections per host    : 1
       Total files transferred : 0
       Total bytes transferred : 0.000KiB
       Total duration          : 2920 ms
       Average transfer rate   : 0.000KiB/s
       Peak transfer rate      : 0.000KiB/s

步骤2：使用下面的命令插入3条记录

CREATE TABLE Cricket (
    PlayerID uuid,
    LastName varchar,
    FirstName varchar,  
    City varchar,
    State varchar,
    PRIMARY KEY (PlayerID));

INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Pendulkar', 'Sachin', 'Mumbai','Maharastra');
INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Vholi', 'Virat', 'Delhi','New Delhi');
INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Sharma', 'Rohit', 'Berhampur','Odisha');

cassandra@node1:~$ sstableloader -d 10.213.61.21 -username cassandra --password cassandra /home/cassandra/data/students_details/cricket-d3576f60960f11ea947b39646348bb4f/snapshots
    Established connection to initial hosts
    Opening sstables and calculating sections to stream

    Summary statistics:
       Connections per host    : 1
       Total files transferred : 0
       Total bytes transferred : 0.000KiB
       Total duration          : 2920 ms
       Average transfer rate   : 0.000KiB/s
       Peak transfer rate      : 0.000KiB/s

第三步：我不小心删除了板球桌

drop table Cricket;

步骤4：需要使用自动快照备份恢复该表 注意：auto_snapshot（默认值：true）启用或禁用在键空间截断或删除表之前是否对数据进行快照。为防止数据丢失，强烈建议使用默认设置

步骤5：查找快照位置和文件

cassandra@node1:~/data/students_details$ cd cricket-88128dc0960d11ea947b39646348bb4f
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f$ ls -lrth
total 0
drwxrwxr-x 2 cassandra cassandra  6 May 14 18:05 backups
drwxrwxr-x 3 cassandra cassandra 43 May 14 18:06 snapshots

步骤6：您将在快照位置获得一个.cql文件，其中包含DDL表

cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$ ls -lrth
total 44K
-rw-rw-r-- 1 cassandra cassandra   92 May 14 18:06 md-1-big-Summary.db
-rw-rw-r-- 1 cassandra cassandra   61 May 14 18:06 md-1-big-Index.db
-rw-rw-r-- 1 cassandra cassandra   16 May 14 18:06 md-1-big-Filter.db
-rw-rw-r-- 1 cassandra cassandra  179 May 14 18:06 md-1-big-Data.db
-rw-rw-r-- 1 cassandra cassandra   92 May 14 18:06 md-1-big-TOC.txt
-rw-rw-r-- 1 cassandra cassandra 4.7K May 14 18:06 md-1-big-Statistics.db
-rw-rw-r-- 1 cassandra cassandra    9 May 14 18:06 md-1-big-Digest.crc32
-rw-rw-r-- 1 cassandra cassandra   43 May 14 18:06 md-1-big-CompressionInfo.db
-rw-rw-r-- 1 cassandra cassandra  891 May 14 18:06 schema.cql
-rw-rw-r-- 1 cassandra cassandra   31 May 14 18:06 manifest.json
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$

more schema.cql
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$ more schema.cql
CREATE TABLE IF NOT EXISTS students_details.cricket (
        playerid uuid PRIMARY KEY,
        city text,
        firstname text,
        lastname text,
        state text)
        WITH ID = 88128dc0-960d-11ea-947b-39646348bb4f
        AND bloom_filter_fp_chance = 0.01
        AND dclocal_read_repair_chance = 0.1
        AND crc_check_chance = 1.0
        AND default_time_to_live = 0
        AND gc_grace_seconds = 864000
        AND min_index_interval = 128
        AND max_index_interval = 2048
        AND memtable_flush_period_in_ms = 0
        AND read_repair_chance = 0.0
        AND speculative_retry = '99PERCENTILE'
        AND comment = ''
        AND caching = { 'keys': 'ALL', 'rows_per_partition': 'NONE' }
        AND compaction = { 'max_threshold': '32', 'min_threshold': '4', 'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy' }
        AND compression = { 'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor' }
        AND cdc = false
        AND extensions = {  };

步骤7：登录数据库并使用该DDL创建表

    apiadmin@cqlsh:coopersdev> use students_details;
    apiadmin@cqlsh:students_details> CREATE TABLE IF NOT EXISTS students_details.cricket (
                        ...         playerid uuid PRIMARY KEY,
                        ...         city text,
                        ...         firstname text,
                        ...         lastname text,
                        ...         state text)
                        ...         WITH ID = 88128dc0-960d-11ea-947b-39646348bb4f
                        ...         AND bloom_filter_fp_chance = 0.01
                        ...         AND dclocal_read_repair_chance = 0.1
                        ...         AND crc_check_chance = 1.0
                        ...         AND default_time_to_live = 0
                        ...         AND gc_grace_seconds = 864000
                        ...         AND min_index_interval = 128
                        ...         AND max_index_interval = 2048
                        ...         AND memtable_flush_period_in_ms = 0
                        ...         AND read_repair_chance = 0.0
                        ...         AND speculative_retry = '99PERCENTILE'
                        ...         AND comment = ''
                        ...         AND caching = { 'keys': 'ALL', 'rows_per_partition': 'NONE' }
                        ...         AND compaction = { 'max_threshold': '32', 'min_threshold': '4', 'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy' }
                        ...         AND compression = { 'chunk_length_in_kb': '64', 'class': 'org.apache.cassandra.io.compress.LZ4Compressor' }
                        ...         AND cdc = false
                        ...         AND extensions = {  };
apiadmin@cqlsh:students_details>

步骤8：将快照文件夹中的所有文件复制到现有的cricket table文件夹

cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$ pwd
/home/cassandra/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$ cp * /home/cassandra/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f/snapshots/dropped-1589479603749-cricket$ cd /home/cassandra/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f$ ls -lrth
total 44K
drwxrwxr-x 2 cassandra cassandra    6 May 14 18:05 backups
drwxrwxr-x 3 cassandra cassandra   43 May 14 18:06 snapshots
-rw-rw-r-- 1 cassandra cassandra  891 May 14 18:11 schema.cql
-rw-rw-r-- 1 cassandra cassandra   92 May 14 18:11 md-1-big-TOC.txt
-rw-rw-r-- 1 cassandra cassandra   92 May 14 18:11 md-1-big-Summary.db
-rw-rw-r-- 1 cassandra cassandra 4.7K May 14 18:11 md-1-big-Statistics.db
-rw-rw-r-- 1 cassandra cassandra   61 May 14 18:11 md-1-big-Index.db
-rw-rw-r-- 1 cassandra cassandra   16 May 14 18:11 md-1-big-Filter.db
-rw-rw-r-- 1 cassandra cassandra    9 May 14 18:11 md-1-big-Digest.crc32
-rw-rw-r-- 1 cassandra cassandra  179 May 14 18:11 md-1-big-Data.db
-rw-rw-r-- 1 cassandra cassandra   43 May 14 18:11 md-1-big-CompressionInfo.db
-rw-rw-r-- 1 cassandra cassandra   31 May 14 18:11 manifest.json
cassandra@node1:~/data/students_details/cricket-88128dc0960d11ea947b39646348bb4f$

步骤9：使用下面的命令，使用sstableloader开始还原表数据

CREATE TABLE Cricket (
    PlayerID uuid,
    LastName varchar,
    FirstName varchar,  
    City varchar,
    State varchar,
    PRIMARY KEY (PlayerID));

INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Pendulkar', 'Sachin', 'Mumbai','Maharastra');
INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Vholi', 'Virat', 'Delhi','New Delhi');
INSERT INTO Cricket (PlayerID, LastName, FirstName, City, State)
VALUES (now(), 'Sharma', 'Rohit', 'Berhampur','Odisha');

cassandra@node1:~$ sstableloader -d 10.213.61.21 -username cassandra --password cassandra /home/cassandra/data/students_details/cricket-d3576f60960f11ea947b39646348bb4f/snapshots
    Established connection to initial hosts
    Opening sstables and calculating sections to stream

    Summary statistics:
       Connections per host    : 1
       Total files transferred : 0
       Total bytes transferred : 0.000KiB
       Total duration          : 2920 ms
       Average transfer rate   : 0.000KiB/s
       Peak transfer rate      : 0.000KiB/s

步骤10：表已成功还原。请验证

 playerid                             | city      | firstname | lastname  | state
--------------------------------------+-----------+-----------+-----------+------------
 d7b12c90-960f-11ea-947b-39646348bb4f | Berhampur |     Rohit |    Sharma |     Odisha
 d7594890-960f-11ea-947b-39646348bb4f |     Delhi |     Virat |     Vholi |  New Delhi
 d7588540-960f-11ea-947b-39646348bb4f |    Mumbai |    Sachin | Pendulkar | Maharastra

---

你是说*.db和其他文件应该直接放在/var/lib/cassandra/data/中，而不是放在/var/lib/cassandra/data/makeyourcase/下？而不是在/var/lib/cassandra/data/after_seaking？编辑对Clarify的响应时，您会说“我认为问题在于您正在将快照数据恢复到快照目录中。它应该在表目录中。”这是我尝试的目录之一。Cassandra仍然没有找到它们。“您可以使用：…”运行特定键空间的快照。“快照部分工作正常，如图所示。”删除数据时，请确保不删除快照文件夹，否则将无法还原它（除非您将其移到另一个位置/计算机）。”，卸载时，将重新创建快照目录。