我使用的java驱动版本:2.1.4
Cassandra版本:dsc-cassandra-2.1.10
cql 的输出给出以下内容
cqlsh 5.0.1 | Cassandra 2.1.10 | CQL spec 3.2.1 | Native protocol v3
我是协议(protocol)V3。但当我尝试将其设置为每个连接超过 128 个请求时,它会引发异常。这似乎是V2 中的限制。解释如下:
以下代码块:
PoolingOptions poolingOptions = new PoolingOptions();
poolingOptions.setCoreConnectionsPerHost(HostDistance.LOCAL, 8);
Cluster cluster = Cluster.builder()
.addContactPoints(x.x.x.x)
.withPoolingOptions(poolingOptions)
.withProtocolVersion(ProtocolVersion.V3)
.build();
System.out.println("Protocol version = "+myCurrentVersion);
System.out.println("LOCAL CORE = "+poolingOptions.getCoreConnectionsPerHost(HostDistance.LOCAL));
System.out.println("LOCAL MAX = "+poolingOptions.getMaxConnectionsPerHost(HostDistance.LOCAL));
System.out.println("Max sim requests = "+poolingOptions.getMaxSimultaneousRequestsPerConnectionThreshold(HostDistance.LOCAL));
System.out.println("Max sim requests per host = "+poolingOptions.getMaxSimultaneousRequestsPerHostThreshold(HostDistance.LOCAL));
poolingOptions
.setMaxSimultaneousRequestsPerHostThreshold(HostDistance.LOCAL, 3000);
poolingOptions
.setMaxSimultaneousRequestsPerConnectionThreshold(HostDistance.LOCAL, 128);
System.out.println("LOCAL CORE = "+poolingOptions.getCoreConnectionsPerHost(HostDistance.LOCAL));
System.out.println("LOCAL MAX = "+poolingOptions.getMaxConnectionsPerHost(HostDistance.LOCAL));
System.out.println("Max sim requests = "+poolingOptions.getMaxSimultaneousRequestsPerConnectionThreshold(HostDistance.LOCAL));
System.out.println("Max sim requests per host = "+poolingOptions.getMaxSimultaneousRequestsPerHostThreshold(HostDistance.LOCAL));
输出为:
Protocol version = V3
LOCAL CORE = 1
LOCAL MAX = 8
Max sim requests = 100
Max sim requests per host = 1024
Exception in thread "main" java.lang.IllegalArgumentException: Max simultaneous requests per connection for LOCAL hosts must be in the range (0, 128)
at com.datastax.driver.core.PoolingOptions.checkRequestsPerConnectionRange(PoolingOptions.java:370)
at com.datastax.driver.core.PoolingOptions.setMaxSimultaneousRequestsPerConnectionThreshold(PoolingOptions.java:175)
at ca.txio.pricehistoryservice.main.ConnectionOptionTest.main(ConnectionOptionTest.java:38)
根据 Cassandra 文档 https://docs.datastax.com/en/developer/java-driver/2.1/manual/native_protocol/ 和 http://docs.datastax.com/en/developer/java-driver/2.1/manual/pooling/
我是协议(protocol)V3。但为什么我限制每个连接 128 个请求。这似乎是V2 中的限制。有人可以解释一下如何找到我实际上是什么版本吗?如果确实是 V3,为什么我不能同时拥有超过 128 个连接?
最佳答案
使用 ProtocolVersion#V3 或更高版本,每个连接最多有 32768 个请求,并且池默认为固定大小 1。您通常会通过允许每个连接更多的并发请求来提高最大容量 (setMaxRequestsPerConnection(主机距离,int))
关于java - Cassandra java驱动程序协议(protocol)版本和连接限制不匹配,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/47024198/