Question

我从另一个cassandra数据文件夹中复制了所有键空间和表格，如何在我的cassandra节点中恢复它。

我没有通常需要恢复的快照。

Answer 1

您可以使用Cassandra Bulk Loader执行此操作。

假设打包安装（包含默认数据和bin位置），请从您的一个节点尝试此操作：

$ sstableloader -d hostname1,hostname2 /var/lib/cassandra/data/yourKeyspaceName/tableName/

查看documentation on the Bulk Loader了解详情。

Answer 2

你可以这样做但是：

您需要知道要还原的所有表的架构。如果您不知道这一点，请使用sstable2json（下面的示例，但这可能很棘手，需要了解sstable2json如何格式化事物）
您必须启动一个新节点，使用派生自1的模式创建密钥空间及其表，然后按照Aaron（BryceAtNetwork23）文档中的描述使用BulkLoader。

使用sstable2json检索模式（脱机进程）的示例，此示例假定您的键空间名称为 test ，表名为 example1 ：

sstable2json /var/lib/cassandra/data/test/example1-55639910d46a11e4b4335dbb0aaeeb24/test-example1-ka-1-Data.db

// output:
WARN  10:25:34 JNA link failure, one or more native method will be unavailable.
[
{"key": "7d700500-d46b-11e4-b433-5dbb0aaeeb24",    <-- key = bytes of what is in the PRIMARY KEY()
 "cells": [["coolguy:","",1427451885901681],       <-- cql3 row marker (empty cell that tells us table was created using cql3)
           ["coolguy:age","29",1427451885901681],  <-- age
           ["coolguy:email:_","coolguy:email:!",1427451885901680,"t",1427451885],        <-- collection cell marker 
           ["coolguy:email:6367406d61696c2e6e6574","",1427451885901681],                 <-- first entry in collection 
           ["coolguy:email:636f6f6c677579383540676d61696c2e636f6d","",1427451885901681], <-- second entry in collection
           ["coolguy:password","xQajKe2fa?af",1427451885901681]]},                       <-- another text field for password
{"key": "52641f40-d46b-11e4-b433-5dbb0aaeeb24",
 "cells": [["lyubent:","",1427451813663728],
           ["lyubent:age","109",1427451813663728],
           ["lyubent:email:_","lyubent:email:!",1427451813663727,"t",1427451813],
           ["lyubent:email:66616b65406162762e6267","",1427451813663728],
           ["lyubent:email:66616b6540676d61696c2e636f6d","",1427451813663728],
           ["lyubent:password","password",1427451813663728]]}
]

以上等同于：

CREATE TABLE test.example1 (
    id timeuuid,
    username text,
    age int,
    email set<text>,
    password text,
    PRIMARY KEY (id, username)
) WITH CLUSTERING ORDER BY (username ASC)
// the below are settings that you have no way of knowing,
// unless you are hardcore enough to start digging through
// system tables with the debug tool, but this is beyond
// the scope of the question.
    AND bloom_filter_fp_chance = 0.01
    AND caching = '{"keys":"ALL", "rows_per_partition":"NONE"}'
    AND comment = ''
    AND compaction = {'min_threshold': '4', 'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy', 'max_threshold': '32'}
    AND compression = {'sstable_compression': 'org.apache.cassandra.io.compress.LZ4Compressor'}
    AND dclocal_read_repair_chance = 0.1
    AND default_time_to_live = 0
    AND gc_grace_seconds = 864000
    AND max_index_interval = 2048
    AND memtable_flush_period_in_ms = 0
    AND min_index_interval = 128
    AND read_repair_chance = 0.0
    AND speculative_retry = '99.0PERCENTILE';

您可以清楚地看到用户名和密码在翻译中丢失，因为它们是关键，但您可以根据以下事实判断出复合键：所有单元格都有一个部分：预先附加，在以上两个条目的例子是coolguy：和lyubent：继续这个你知道他们的密钥是由PRIMARY KEY（东西？，用户名文本）组成的。如果您很幸运，您的主键很简单，并且从中调试架构将是直截了当的，如果不在此处发布，我们将看到我们能走多远。

从cassandra数据文件夹恢复所有键空间和表

2 个答案: