sql-server - Akka .NET 连接池超时问题

Question

我们正在使用 Akka.NET 创建一个新系统，并有一个带有分片和持久性的基本集群设置。

我们使用官方文档和一些 Petabridge 博客文章来让分片正常工作。但是，我们遇到了一个问题，即分片超出了 SQL Server 连接池允许的最大连接数。因此，我们收到以下消息...

2017-04-20 14:04:31.433 +01:00 [Warning] "Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached."

我们相信当分片更新分片日志时会发生这种情况。

为什么分片模块不能正确管理其 SQL 连接？这里有配置问题吗？

发生这种错误时是否可以重试？就目前而言，我们会丢失此错误的每个实例的消息。

这是相关的HOCON

cluster.sharding {
    journal-plugin-id = "akka.persistence.journal.sharding"
    snapshot-plugin-id = "akka.persistence.snapshot-store.sharding"
}
persistence {
    journal {
        plugin = "akka.persistence.journal.sql-server"
        sql-server {
            class = "Akka.Persistence.SqlServer.Journal.SqlServerJournal, Akka.Persistence.SqlServer"
            connection-string = "Server=.;Database=akkasystem;Integrated Security=true"
            schema-name = dbo
            auto-initialize = on
        }
        # a separate config used by cluster sharding only 
        sharding {
            connection-string = "Server=.;Database=akkasystem;Integrated Security=true"
            auto-initialize = on
            plugin-dispatcher = "akka.actor.default-dispatcher"
            class = "Akka.Persistence.SqlServer.Journal.SqlServerJournal, Akka.Persistence.SqlServer"
            connection-timeout = 30s
            schema-name = dbo
            table-name = ShardingJournal
            timestamp-provider = "Akka.Persistence.Sql.Common.Journal.DefaultTimestampProvider, Akka.Persistence.Sql.Common"
            metadata-table-name = ShardingMetadata
        }
    }
    snapshot-store {
        sharding {
            class = "Akka.Persistence.SqlServer.Snapshot.SqlServerSnapshotStore, Akka.Persistence.SqlServer"
            plugin-dispatcher = "akka.actor.default-dispatcher"
            connection-string = "Server=.;Database=akkasystem;Integrated Security=true"
            connection-timeout = 30s
            schema-name = dbo
            table-name = ShardingSnapshotStore
            auto-initialize = on
        }
    }
}

Answer 1

这可能表明 SQL 日志被大量传入事件淹没，连接超时触发，而事件正在等待池中的下一个连接被释放。

从您的配置中我怀疑，如果您开始持久化事件并创建高比率的分片/实体，这可能会发生。现有的 SQL 日志将在不久的将来获得显着的速度提升(参见 batching journals)。希望这可以帮助解决您的问题。