限制jdbc连接池固定量

Question

嗨，我使用micronaut数据和各种jdbc连接池。我第一次有hikari，也尝试了tomcat的一个。

我假设将数据源设置为最大池大小：10 会导致最多 10 个打开连接。但似乎有很多开场和闭幕正在进行。再加上同时处理大量请求，它使用的不仅仅是 10 个连接。问题是，Azure postgresql 总共只允许 100 个连接。

目前我有7个应用程序在访问这个数据库。我希望最多能有70个连接。但实际上要多得多。

我也尝试使用tomcat jdbc池，他的行为有点不同。但也使用超过10个连接。我还使用 java 分析器进行了检查，发现有时每秒多达 100 个打开/关闭连接事件。

除了使用第二个数据库之外，在这种情况下如何行动的任何建议。我希望这个池可以缓冲这些调用，尤其是因为它们来自Kafka的主题。但是，似乎有所不同。

---编辑添加光日志

这是光的日志输出

2020-12-11 11:59:40,983 [main] DEBUG com.zaxxer.hikari.HikariConfig - Driver class org.postgresql.Driver found in Thread context class loader jdk.internal.loader.ClassLoaders$AppClassLoader@2c13da15
2020-12-11 11:59:40,993 [main] DEBUG com.zaxxer.hikari.HikariConfig - HikariPool-1 - configuration:
2020-12-11 11:59:40,999 [main] DEBUG com.zaxxer.hikari.HikariConfig - allowPoolSuspension.............false
2020-12-11 11:59:41,000 [main] DEBUG com.zaxxer.hikari.HikariConfig - autoCommit......................true
2020-12-11 11:59:41,000 [main] DEBUG com.zaxxer.hikari.HikariConfig - catalog.........................none
2020-12-11 11:59:41,001 [main] DEBUG com.zaxxer.hikari.HikariConfig - connectionInitSql...............none
2020-12-11 11:59:41,001 [main] DEBUG com.zaxxer.hikari.HikariConfig - connectionTestQuery............."SELECT 1;"
2020-12-11 11:59:41,001 [main] DEBUG com.zaxxer.hikari.HikariConfig - connectionTimeout...............30000
2020-12-11 11:59:41,002 [main] DEBUG com.zaxxer.hikari.HikariConfig - dataSource......................none
2020-12-11 11:59:41,002 [main] DEBUG com.zaxxer.hikari.HikariConfig - dataSourceClassName.............none
2020-12-11 11:59:41,002 [main] DEBUG com.zaxxer.hikari.HikariConfig - dataSourceJNDI..................none
2020-12-11 11:59:41,003 [main] DEBUG com.zaxxer.hikari.HikariConfig - dataSourceProperties............{password=<masked>}
2020-12-11 11:59:41,004 [main] DEBUG com.zaxxer.hikari.HikariConfig - driverClassName................."org.postgresql.Driver"
2020-12-11 11:59:41,004 [main] DEBUG com.zaxxer.hikari.HikariConfig - exceptionOverrideClassName......none
2020-12-11 11:59:41,004 [main] DEBUG com.zaxxer.hikari.HikariConfig - healthCheckProperties...........{}
2020-12-11 11:59:41,005 [main] DEBUG com.zaxxer.hikari.HikariConfig - healthCheckRegistry.............none
2020-12-11 11:59:41,005 [main] DEBUG com.zaxxer.hikari.HikariConfig - idleTimeout.....................600000
2020-12-11 11:59:41,005 [main] DEBUG com.zaxxer.hikari.HikariConfig - initializationFailTimeout.......1
2020-12-11 11:59:41,006 [main] DEBUG com.zaxxer.hikari.HikariConfig - isolateInternalQueries..........false
2020-12-11 11:59:41,007 [main] DEBUG com.zaxxer.hikari.HikariConfig - jdbcUrl.........................jdbc:postgresql://URL:5432/postgres
2020-12-11 11:59:41,007 [main] DEBUG com.zaxxer.hikari.HikariConfig - leakDetectionThreshold..........0
2020-12-11 11:59:41,007 [main] DEBUG com.zaxxer.hikari.HikariConfig - maxLifetime.....................1800000
2020-12-11 11:59:41,008 [main] DEBUG com.zaxxer.hikari.HikariConfig - maximumPoolSize.................10
2020-12-11 11:59:41,008 [main] DEBUG com.zaxxer.hikari.HikariConfig - metricRegistry..................none
2020-12-11 11:59:41,008 [main] DEBUG com.zaxxer.hikari.HikariConfig - metricsTrackerFactory...........none
2020-12-11 11:59:41,009 [main] DEBUG com.zaxxer.hikari.HikariConfig - minimumIdle.....................10
2020-12-11 11:59:41,009 [main] DEBUG com.zaxxer.hikari.HikariConfig - password........................<masked>
2020-12-11 11:59:41,009 [main] DEBUG com.zaxxer.hikari.HikariConfig - poolName........................"HikariPool-1"
2020-12-11 11:59:41,010 [main] DEBUG com.zaxxer.hikari.HikariConfig - readOnly........................false
2020-12-11 11:59:41,010 [main] DEBUG com.zaxxer.hikari.HikariConfig - registerMbeans..................false
2020-12-11 11:59:41,011 [main] DEBUG com.zaxxer.hikari.HikariConfig - scheduledExecutor...............none
2020-12-11 11:59:41,011 [main] DEBUG com.zaxxer.hikari.HikariConfig - schema.........................."SCHEMA"
2020-12-11 11:59:41,011 [main] DEBUG com.zaxxer.hikari.HikariConfig - threadFactory...................internal
2020-12-11 11:59:41,011 [main] DEBUG com.zaxxer.hikari.HikariConfig - transactionIsolation............default
2020-12-11 11:59:41,012 [main] DEBUG com.zaxxer.hikari.HikariConfig - username........................"USERNAME"
2020-12-11 11:59:41,012 [main] DEBUG com.zaxxer.hikari.HikariConfig - validationTimeout...............5000

Answer 1

我找到了错误——或者至少找到了解决问题的方法。

在将一些数据保存到数据库中的同时，我还尝试更新缓存。但是由于咖啡因加载缓存的变化，每次保存也会导致对完全相同的数据对象实例进行获取。

我的猜测是由于造成麻烦的交易。将 cache.get 替换为 cache.replace 后，一切正常。