golang源码分析：etcd（3）

golangLeetcode

发布于 2023-08-09 15:14:50

1690

发布于 2023-08-09 15:14:50

搭完集群后，我开始体验下etcd如何使用

1，设置key，进行前缀查询操作

ENDPOINTS=http://127.0.0.1:22379
etcdctl --endpoints=$ENDPOINTS put web1 value1
etcdctl --endpoints=$ENDPOINTS put web2 value2
OK
etcdctl --endpoints=$ENDPOINTS put web3 value3

查询

etcdctl --endpoints=$ENDPOINTS get web --prefix
web1
value1
web2
value2
web3
value3

2，前缀删除

etcdctl --endpoints=$ENDPOINTS put key myvalue
etcdctl --endpoints=$ENDPOINTS del key

etcdctl --endpoints=$ENDPOINTS put k1 value1
etcdctl --endpoints=$ENDPOINTS put k2 value2
etcdctl --endpoints=$ENDPOINTS del k --prefix
2

3，事务操作txn

etcdctl --endpoints=$ENDPOINTS put user1 bad
etcdctl --endpoints=$ENDPOINTS txn --interactive
OK
compares:
value("user1") = "bad"

success requests (get, put, del):
del user1

failure requests (get, put, del):
put user1 good

SUCCESS

1

4，watch操作

在一个console进行watch，另一个console进行key的操作

etcdctl --endpoints=$ENDPOINTS watch stock1

etcdctl --endpoints=$ENDPOINTS put stock1 1000

当然也可以watch前缀

etcdctl --endpoints=$ENDPOINTS watch stock --prefix
etcdctl --endpoints=$ENDPOINTS put stock1 10
etcdctl --endpoints=$ENDPOINTS put stock2 20

5，租期

% etcdctl --endpoints=$ENDPOINTS lease grant 300
lease 414688a849143a15 granted with TTL(300s)

 % etcdctl --endpoints=$ENDPOINTS put sample value --lease=414688a849143a15
etcdctl --endpoints=$ENDPOINTS get sample

OK
sample
value

操作的时候需要指定返回的租期id

% etcdctl --endpoints=$ENDPOINTS get sample                               
sample
value

6，分布式锁

 % etcdctl --endpoints=$ENDPOINTS lock mutex1
mutex1/414688a849143a1d

在另一个console尝试加锁，会一直阻塞，直到前者释放锁

% ENDPOINTS=http://127.0.0.1:22379
% etcdctl --endpoints=$ENDPOINTS lock mutex1
mutex1/414688a849143a21

7，选举

% etcdctl --endpoints=$ENDPOINTS elect one p1
one/414688a849143a2a
p1

% etcdctl --endpoints=$ENDPOINTS elect one p2
p2

8，查看数据状态


% etcdctl --write-out=table --endpoints=$ENDPOINTS endpoint status

+------------------------+------------------+---------------+-----------------+---------+----------------+-----------+------------+-----------+------------+--------------------+--------+
|        ENDPOINT        |        ID        |    VERSION    | STORAGE VERSION | DB SIZE | DB SIZE IN USE | IS LEADER | IS LEARNER | RAFT TERM | RAFT INDEX | RAFT APPLIED INDEX | ERRORS |
+------------------------+------------------+---------------+-----------------+---------+----------------+-----------+------------+-----------+------------+--------------------+--------+
| http://127.0.0.1:22379 | 91bc3c398fb3c146 | 3.6.0-alpha.0 |           3.6.0 |   33 kB |          33 kB |     false |      false |         2 |         37 |                 37 |        |
+------------------------+------------------+---------------+-----------------+---------+----------------+-----------+------------+-----------+------------+--------------------+--------+

% etcdctl --endpoints=$ENDPOINTS endpoint health
http://127.0.0.1:22379 is healthy: successfully committed proposal: took = 15.993027ms

9，数据持久化备份

% etcdctl --endpoints=$ENDPOINTS snapshot save my.db

{"level":"info","ts":"2023-06-11T16:48:51.176005+0800","caller":"snapshot/v3_snapshot.go:67","msg":"created temporary db file","path":"my.db.part"}
{"level":"info","ts":"2023-06-11T16:48:51.178707+0800","logger":"client","caller":"v3@v3.6.0-alpha.0/maintenance.go:237","msg":"opened snapshot stream; downloading"}
{"level":"info","ts":"2023-06-11T16:48:51.214419+0800","caller":"snapshot/v3_snapshot.go:75","msg":"fetching snapshot","endpoint":"http://127.0.0.1:22379"}
{"level":"info","ts":"2023-06-11T16:48:51.230865+0800","logger":"client","caller":"v3@v3.6.0-alpha.0/maintenance.go:302","msg":"completed snapshot read; closing"}
{"level":"info","ts":"2023-06-11T16:48:51.245575+0800","caller":"snapshot/v3_snapshot.go:90","msg":"fetched snapshot","endpoint":"http://127.0.0.1:22379","size":"33 kB","took":"68.257765ms","etcd-version":"3.6.0"}
{"level":"info","ts":"2023-06-11T16:48:51.247532+0800","caller":"snapshot/v3_snapshot.go:100","msg":"saved","path":"my.db"}
Snapshot saved at my.db
Server version 3.6.0

% etcdctl --write-out=table --endpoints=$ENDPOINTS snapshot status my.db

10，版本v2和v3之间迁移


# write key in etcd version 2 store
export ETCDCTL_API=2
etcdctl --endpoints=http://$ENDPOINT set foo bar

# read key in etcd v2
etcdctl --endpoints=$ENDPOINTS --output="json" get foo

# stop etcd node to migrate, one by one

# migrate v2 data
export ETCDCTL_API=3
etcdctl --endpoints=$ENDPOINT migrate --data-dir="default.etcd" --wal-dir="default.etcd/member/wal"

# restart etcd node after migrate, one by one

# confirm that the key got migrated
etcdctl --endpoints=$ENDPOINTS get /foo

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原始发表：2023-06-17，如有侵权请联系 cloudcommunity@tencent.com 删除

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