我们最近升级到了Play 2.7.0，并使用play2-reactivemongo版本0.16.2和reactmongo 0.16.3。我们使用reactivemongo-shaded-native但也尝试不使用。
我们正在连接到具有3个节点的副本集，即MongoDB Atlas上的MongoDB 3.6.10。
初始连接正常，服务运行了一段时间。
但是最后我们遇到了这个错误：
[error] 2019-02-15 09:40:30,466 r.api.Failover2 - [Supervisor-1/Connection-2] Got an error, no more attempts to do. Completing with a failure...
reactivemongo.core.actors.Exceptions$PrimaryUnavailableException: MongoError['No primary node is available! (Supervisor-1/Connection-2)']
Caused by: reactivemongo.core.actors.Exceptions$InternalState: null
at reactivemongo.ConnectAll$IsMaster(400, {{NodeSet Some(PlayappDevelopment-shard-0) Node[playappdevelopment-shard-00-00-tedsb.mongodb.net:27017: Unknown (20/20 available connections), latency=9223372036854775807, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-01-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=135, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-02-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=140, authenticated={Authenticated(admin,playapp_rw)}] }})(<time:1550223615628>)
at reactivemongo.IsMaster(400, {{NodeSet Some(PlayappDevelopment-shard-0) Node[playappdevelopment-shard-00-00-tedsb.mongodb.net:27017: Unknown (20/20 available connections), latency=9223372036854775807, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-01-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=135, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-02-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=21, authenticated={Authenticated(admin,playapp_rw)}] }})(<time:1550223615626>)
at reactivemongo.ConnectAll$IsMaster(399, {{NodeSet Some(PlayappDevelopment-shard-0) Node[playappdevelopment-shard-00-00-tedsb.mongodb.net:27017: Unknown (20/20 available connections), latency=9223372036854775807, authenticated={}] | Node[playappdevelopment-shard-00-01-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=135, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-02-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=21, authenticated={Authenticated(admin,playapp_rw)}] }})(<time:1550223615623>)
at reactivemongo.IsMaster(399, {{NodeSet Some(PlayappDevelopment-shard-0) Node[playappdevelopment-shard-00-00-tedsb.mongodb.net:27017: Unknown (20/20 available connections), latency=9223372036854775807, authenticated={}] | Node[playappdevelopment-shard-00-01-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=17, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-02-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=21, authenticated={Authenticated(admin,playapp_rw)}] }})(<time:1550223615622>)
at reactivemongo.RefreshAll({{NodeSet Some(PlayappDevelopment-shard-0) Node[playappdevelopment-shard-00-00-tedsb.mongodb.net:27017: Primary (20/20 available connections), latency=30591, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-01-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=17, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-02-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=21, authenticated={Authenticated(admin,playapp_rw)}] }})(<time:1550223615486>)
at reactivemongo.PrimaryUnavailable(<time:1550223615485>)
at reactivemongo.ConnectAll({{NodeSet Some(PlayappDevelopment-shard-0) Node[playappdevelopment-shard-00-00-tedsb.mongodb.net:27017: Primary (20/20 available connections), latency=30591, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-01-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=17, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-02-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=21, authenticated={Authenticated(admin,playapp_rw)}] }})(<time:1550223615475>)
at reactivemongo.ConnectAll$IsMaster(397, {{NodeSet Some(PlayappDevelopment-shard-0) Node[playappdevelopment-shard-00-00-tedsb.mongodb.net:27017: Primary (20/20 available connections), latency=30591, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-01-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=17, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-02-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=21, authenticated={Authenticated(admin,playapp_rw)}] }})(<time:1550223605498>)
at reactivemongo.IsMaster(397, {{NodeSet Some(PlayappDevelopment-shard-0) Node[playappdevelopment-shard-00-00-tedsb.mongodb.net:27017: Primary (20/20 available connections), latency=30591, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-01-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=17, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-02-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=15, authenticated={Authenticated(admin,playapp_rw)}] }})(<time:1550223605498>)
at reactivemongo.ConnectAll$IsMaster(396, {{NodeSet Some(PlayappDevelopment-shard-0) Node[playappdevelopment-shard-00-00-tedsb.mongodb.net:27017: Primary (20/20 available connections), latency=30591, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-01-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=17, authenticated={Authenticated(admin,playapp_rw)}] | Node[playappdevelopment-shard-00-02-tedsb.mongodb.net:27017: Secondary (20/20 available connections), latency=15, authenticated={Authenticated(admin,playapp_rw)}] }})(<time:1550223605493>)
还有这个：
[error] 2019-02-15 09:40:25,157 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] Oups. 80193 not found! complete message is Response(MessageHeader(16775938,220053,80193,1), Reply(8,0,0,1), ResponseInfo(b0706d7f))
[error] 2019-02-15 09:40:25,720 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] Oups. 79580 not found! complete message is Response(MessageHeader(16776408,220065,79580,1), Reply(8,0,0,1), ResponseInfo(5c65523c))
[error] 2019-02-15 09:40:26,616 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] Oups. 80346 not found! complete message is Response(MessageHeader(16776173,220060,80346,1), Reply(8,0,0,1), ResponseInfo(5613ea02))
[error] 2019-02-15 09:40:26,702 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] Oups. 80457 not found! complete message is Response(MessageHeader(16776643,220079,80457,1), Reply(8,0,0,1), ResponseInfo(2fa23bb9))
[error] 2019-02-15 09:40:29,612 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] Oups. 80174 not found! complete message is Response(MessageHeader(16776878,220102,80174,1), Reply(8,0,0,1), ResponseInfo(4faa6eec))
[error] 2019-02-15 09:40:30,257 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] Oups. 80191 not found! complete message is Response(MessageHeader(16776643,220111,80191,1), Reply(8,0,0,1), ResponseInfo(1fb6b5e0))
看来应用程序无法（完全）恢复-20个请求中有1个成功。
2019-02-15 09:59:45,476 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] Node[playappdevelopment-shard-00-00-tedsb.mongodb.net:27017: \
Unknown (20/20 available connections), latency=9223372036854775807, authenticated={Authenticated(admin,playapp_rw)}] \
hasn't answered in time to last ping! Please check its connectivity
有许多“无请求通道”消息：
2019-03-05 15:02:58,433 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48879, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:58,580 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48880, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:58,678 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48881, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:58,777 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48882, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:58,874 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48883, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:58,972 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48884, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:59,069 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48885, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:59,220 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48886, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:59,318 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48887, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:59,416 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48888, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:59,514 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48889, 0, Query(0,assets.$cmd,0,1), Primary, None)
2019-03-05 15:02:59,611 r.c.a.MongoDBSystem - [Supervisor-1/Connection-2] No channel for request: Request(48890, 0, Query(0,assets.$cmd,0,1), Primary, None)
这似乎与对Play HTTP服务器的大量并发请求有关，这可能会使到达主节点的所有可用通道饱和，从而导致主状态刷新失败。
显然，当连接到只有一个节点的本地副本集时，我们没有这个问题。
问题是，我该如何解决？
任何人都可以理解所提供的日志消息吗？
我的分析正确吗？ ReactiveMongo是否会因为通道只是“忙”而无法查询主要状态，这会发生吗？
更新：我们从ReactiveMongo（在过去的4年中为我们提供了很好的服务）切换到了正式的mongo-scala驱动程序-这确实很痛苦，而且仍然是（主要是因为“ Registry”没有编译时间） -type-safety概念传递
Class[T]等），但我们不再看到连接问题。 最佳答案
将Reactive Mongo升级到0.17.1后，它对我们有用