MongoDB副本集配置系列四：节点的关闭顺序

gechongrepl:ARBITER> use admin
switched to db admin
gechongrepl:ARBITER> db.shutdownServer()

再次关闭S：

S变为了：ggechongrepl:SECONDARY> 

gechongrepl:SECONDARY> use admin
switched to db admin
gechongrepl:SECONDARY> db.shutdownServer()

2：关闭顺序PAS : 已经验证，不报错。

3：关闭顺序SAP

S：

gechongrepl:SECONDARY> use admin
switched to db admin
gechongrepl:SECONDARY> db.shutdownServer()

A：

gechongrepl:ARBITER> use admin
switched to db admin
gechongrepl:ARBITER> db.shutdownServer()

P：

主变为了：gechongrepl:SECONDARY>

gechongrepl:SECONDARY> use admin
switched to db admin
gechongrepl:SECONDARY> db.shutdownServer()

4：关闭顺序SPA

S:

gechongrepl:SECONDARY> use admin
switched to db admin
gechongrepl:SECONDARY> db.shutdownServer()

P：

gechongrepl:PRIMARY> use admin
switched to db admin
gechongrepl:PRIMARY> db.shutdownServer()
assert failed : unexpected error: Error: shutdownServer failed: No electable secondaries caught up as of 2015-05-28T23:59:19.685-0700
Error: assert failed : unexpected error: Error: shutdownServer failed: No electable secondaries caught up as of 2015-05-28T23:59:19.685-0700
    at Error (<anonymous>)
    at doassert (src/mongo/shell/assert.js:11:14)
    at assert (src/mongo/shell/assert.js:20:5)
    at DB.shutdownServer (src/mongo/shell/db.js:212:9)
    at (shell):1:4
2015-05-28T23:59:19.702-0700 E QUERY    Error: assert failed : unexpected error: Error: shutdownServer failed: No electable secondaries caught up as of 2015-05-28T23:59:19.685-0700
    at Error (<anonymous>)
    at doassert (src/mongo/shell/assert.js:11:14)
    at assert (src/mongo/shell/assert.js:20:5)
    at DB.shutdownServer (src/mongo/shell/db.js:212:9)
    at (shell):1:4 at src/mongo/shell/assert.js:13

A：

gechongrepl:ARBITER> use admin
switched to db admin
gechongrepl:ARBITER> db.shutdownServer()

再次关闭P：

gechongrepl:PRIMARY> use admin
switched to db admin
2015-05-29T00:00:44.938-0700 I NETWORK  DBClientCursor::init call() failed
2015-05-29T00:00:44.940-0700 I NETWORK  trying reconnect to 127.0.0.1:27017 (127.0.0.1) failed
2015-05-29T00:00:44.941-0700 I NETWORK  reconnect 127.0.0.1:27017 (127.0.0.1) ok
gechongrepl:SECONDARY> db.shutdownServer()

下面猜测：在关闭最后的Primary节点之前，先关掉仲裁节点即不会报错。（首先关掉Primary节点，还有其他Secondary不属于这种情况）

5：关闭顺序APS ： 不会报错
6：关闭顺序ASP ： 不会报错

验证猜测：

5：关闭顺序APS

A：

gechongrepl:ARBITER> use admin
switched to db admin
gechongrepl:ARBITER> db.shutdownServer()

P：

gechongrepl:PRIMARY> use admin
switched to db admin
gechongrepl:PRIMARY> db.shutdownServer()

S：因为仲裁节点关闭了。所以Primary节点不会再自动切换

gechongrepl:SECONDARY> use admin
switched to db admin
gechongrepl:SECONDARY> db.shutdownServer()

6：关闭顺序ASP

A：

gechongrepl:ARBITER> use admin
switched to db admin
gechongrepl:ARBITER> db.shutdownServer()

S：

gechongrepl:SECONDARY> use admin
switched to db admin
gechongrepl:SECONDARY> db.shutdownServer()

P：

gechongrepl:PRIMARY> 
2015-05-29T00:12:23.962-0700 I NETWORK  DBClientCursor::init call() failed
2015-05-29T00:12:23.965-0700 I NETWORK  trying reconnect to 127.0.0.1:27017 (127.0.0.1) failed
2015-05-29T00:12:23.966-0700 I NETWORK  reconnect 127.0.0.1:27017 (127.0.0.1) ok
gechongrepl:SECONDARY> 
gechongrepl:SECONDARY> use admin
switched to db admin
gechongrepl:SECONDARY> db.shutdownServer()

总结：

1：先关闭从节点、仲裁节点。或者先关闭仲裁节点，最后关闭从节点。则：主节点自动变为从节点

2：先关闭主节点，则从节点自动变为主节点，在仲裁节点关闭之前，新主节点不能关闭

初始化的时候主从节点受priority的影响

priority: 是优先级，默认为1，优先级0为被动节点，不能成为活跃节点。优先级不位0则按照有大到小选出活跃节点。

MongoDB副本集配置系列四：节点的关闭顺序

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