迁移单个实例
本章介绍了将单个实例从 Neo4j 3.5 直接迁移到 4.x 的必要步骤。
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将单个实例从 Neo4j 3.5 迁移到 4.x 需要停机。因此，建议在类似生产的环境中执行测试迁移，以获取停机时间的相关信息。 |
先决条件
确保您已完成 迁移清单 上的所有任务。
准备迁移
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验证您是否已关闭 Neo4j DBMS。您可以检查 neo4j.log。
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安装您要迁移到的 Neo4j 版本。有关如何安装您正在使用的发行版的更多信息，请参阅 操作手册 → 安装。
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用您在 准备新的 neo4j.conf 文件供新安装使用 部分中准备的 neo4j.conf 文件替换它。
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复制用于加密的所有文件，例如私钥、公钥证书以及受信任目录和已吊销目录的内容（位于 <neo4j-home>/certificates/ 中）。
如果您的旧安装具有以
dbms.directories.*开头的修改后的配置或设置dbms.active_database，请验证新的neo4j.conf文件是否已正确配置以查找这些目录。 -
如果您使用的是自定义插件，请确保它们已更新并与新版本兼容，并将它们放在 /plugins 目录中。
迁移数据
使用 4.0 Neo4j 管理工具，迁移 3.5 Neo4j 的数据存储。 neo4j-admin copy 命令还会删除任何不一致的节点、属性和关系，并且不会将它们复制到新创建的存储中。
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从 <neo4j-home> 文件夹中，运行以下命令来复制数据存储。您需要指定旧存储位置以及要更新的目标数据库的名称
bin/neo4j-admin copy --from-path=/path/to/3.5.x/graph.db --to-database=<db_name>Starting to copy store, output will be saved to: $neo4j_home/logs/neo4j-admin-copy-2020-11-26.16.07.19.log 2020-11-26 16:07:19.939+0000 INFO [StoreCopy] ### Copy Data ### 2020-11-26 16:07:19.940+0000 INFO [StoreCopy] Source: /path/to/3.5.x/graph.db (page cache 8m) 2020-11-26 16:07:19.940+0000 INFO [StoreCopy] Target: $neo4j_home/data/databases/database (page cache 8m) 2020-11-26 16:07:19.940+0000 INFO [StoreCopy] Empty database created, will start importing readable data from the source. 2020-11-26 16:07:21.661+0000 INFO [o.n.i.b.ImportLogic] Import starting Import starting 2020-11-26 16:07:21.699+0000 Estimated number of nodes: 50.00 k Estimated number of node properties: 50.00 k Estimated number of relationships: 0.00 Estimated number of relationship properties: 50.00 k Estimated disk space usage: 2.680MiB Estimated required memory usage: 8.598MiB (1/4) Node import 2020-11-26 16:07:22.220+0000 Estimated number of nodes: 50.00 k Estimated disk space usage: 1.698MiB Estimated required memory usage: 8.598MiB .......... .......... .......... .......... .......... 5% ∆239ms .......... .......... .......... .......... .......... 10% ∆1ms .......... .......... .......... .......... .......... 15% ∆1ms .......... .......... .......... .......... .......... 20% ∆0ms .......... .......... .......... .......... .......... 25% ∆1ms .......... .......... .......... .......... .......... 30% ∆0ms .......... .......... .......... .......... .......... 35% ∆0ms .......... .......... .......... .......... .......... 40% ∆1ms .......... .......... .......... .......... .......... 45% ∆0ms .......... .......... .......... .......... .......... 50% ∆1ms .......... .......... .......... .......... .......... 55% ∆0ms .......... .......... .......... .......... .........- 60% ∆51ms .......... .......... .......... .......... .......... 65% ∆0ms .......... .......... .......... .......... .......... 70% ∆0ms .......... .......... .......... .......... .......... 75% ∆1ms .......... .......... .......... .......... .......... 80% ∆0ms .......... .......... .......... .......... .......... 85% ∆0ms .......... .......... .......... .......... .......... 90% ∆1ms .......... .......... .......... .......... .......... 95% ∆0ms .......... .......... .......... .......... .......... 100% ∆0ms (2/4) Relationship import 2020-11-26 16:07:22.543+0000 Estimated number of relationships: 0.00 Estimated disk space usage: 1006KiB Estimated required memory usage: 15.60MiB (3/4) Relationship linking 2020-11-26 16:07:22.879+0000 Estimated required memory usage: 7.969MiB (4/4) Post processing 2020-11-26 16:07:23.272+0000 Estimated required memory usage: 7.969MiB -......... .......... .......... .......... .......... 5% ∆356ms .......... .......... .......... .......... .......... 10% ∆0ms .......... .......... .......... .......... .......... 15% ∆1ms .......... .......... .......... .......... .......... 20% ∆0ms .......... .......... .......... .......... .......... 25% ∆0ms .......... .......... .......... .......... .......... 30% ∆1ms .......... .......... .......... .......... .......... 35% ∆0ms .......... .......... .......... .......... .......... 40% ∆0ms .......... .......... .......... .......... .......... 45% ∆1ms .......... .......... .......... .......... .......... 50% ∆0ms .......... .......... .......... .......... .......... 55% ∆0ms .......... .......... .......... .......... .......... 60% ∆0ms .......... .......... .......... .......... .......... 65% ∆1ms .......... .......... .......... .......... .......... 70% ∆0ms .......... .......... .......... .......... .......... 75% ∆0ms .......... .......... .......... .......... .......... 80% ∆0ms .......... .......... .......... .......... .......... 85% ∆0ms .......... .......... .......... .......... .......... 90% ∆0ms .......... .......... .......... .......... .......... 95% ∆1ms .......... .......... .......... .......... .......... 100% ∆0ms IMPORT DONE in 2s 473ms. Imported: 1 nodes 0 relationships 1 properties Peak memory usage: 15.60MiB 2020-11-26 16:07:24.140+0000 INFO [o.n.i.b.ImportLogic] Import completed successfully, took 2s 473ms. Imported: 1 nodes 0 relationships 1 properties 2020-11-26 16:07:24.668+0000 INFO [StoreCopy] Import summary: Copying of 100704 records took 4 seconds (25176 rec/s). Unused Records 100703 (99%) Removed Records 0 (0%) 2020-11-26 16:07:24.669+0000 INFO [StoreCopy] ### Extracting schema ### 2020-11-26 16:07:24.669+0000 INFO [StoreCopy] Trying to extract schema... 2020-11-26 16:07:24.920+0000 INFO [StoreCopy] ... found 1 schema definitions. The following can be used to recreate the schema: 2020-11-26 16:07:24.922+0000 INFO [StoreCopy] CALL db.createIndex('index_5c0607ad', ['Person'], ['name'], 'native-btree-1.0', {`spatial.cartesian-3d.min`: [-1000000.0, -1000000.0, -1000000.0],`spatial.cartesian.min`: [-1000000.0, -1000000.0],`spatial.wgs-84.min`: [-180.0, -90.0],`spatial.cartesian-3d.max`: [1000000.0, 1000000.0, 1000000.0],`spatial.cartesian.max`: [1000000.0, 1000000.0],`spatial.wgs-84-3d.min`: [-180.0, -90.0, -1000000.0],`spatial.wgs-84-3d.max`: [180.0, 90.0, 1000000.0],`spatial.wgs-84.max`: [180.0, 90.0]}) 2020-11-26 16:07:24.923+0000 INFO [StoreCopy] You have to manually apply the above commands to the database when it is stared to recreate the indexes and constraints. The commands are saved to $neo4j_home/logs/neo4j-admin-copy-2020-11-26.16.07.19.log as well for reference.使用直接路径时，索引不会自动迁移，因此您必须重新创建它们。运行存储迁移后，
neo4j-admin copy命令会提取模式并生成一个命令列表，您可以使用这些命令在新的 4.x 存储上重新创建模式。重新创建模式命令也会保存在迁移日志文件中，该文件位于 /logs 目录中。 -
启动服务器。
bin/neo4j start或
systemctl start neo4j复制数据库不会自动创建它。因此，如果您在 Cypher Shell 或 Neo4j 浏览器中运行
SHOW DATABASES，它将不可见。 -
登录到 Cypher® Shell 命令行控制台，将活动数据库更改为
system（:USE system;），并创建<db_name>数据库。有关 Cypher Shell 命令行界面 (CLI) 以及如何使用它的更多信息，请参阅 操作手册 → Cypher Shell。CREATE DATABASE <db_name>; -
使用新数据库（
:USE <db_name>;），重新创建neo4j-admin copy命令识别出的任何索引或约束。CALL db.createIndex('index_5c0607ad', ['Person'], ['name'], 'native-btree-1.0', {`spatial.cartesian-3d.min`: [-1000000.0, -1000000.0, -1000000.0],`spatial.cartesian.min`: [-1000000.0, -1000000.0],`spatial.wgs-84.min`: [-180.0, -90.0],`spatial.cartesian-3d.max`: [1000000.0, 1000000.0, 1000000.0],`spatial.cartesian.max`: [1000000.0, 1000000.0],`spatial.wgs-84-3d.min`: [-180.0, -90.0, -1000000.0],`spatial.wgs-84-3d.max`: [180.0, 90.0, 1000000.0],`spatial.wgs-84.max`: [180.0, 90.0]});