CODEWITHSUNDEEP
cassandradatastaxcassandra-3.0
Vishal Sharma
Vishal Sharma

Reputation: 1750

Number of connections per host in Datastax C++ driver

I've not been able to understand the role of a 'connection' in the execution of a query on a host.

cass_cluster_set_core_connections_per_host sets the number of connections made to each server in each IO thread. Why is this parameter configurable? What's the benefit of having more than 1 connection per IO thread? What decides the optimum value for this parameter?

Upvotes: 2

Views: 429

Answers (1)

Alex Ott
Alex Ott

Reputation: 87234

This function sets the initial number of connections per host, and it could be increased up to value set by cass_cluster_set_max_connections_per_host function (by default it's 2). New connection is created when the number of in-flight request is greater than set by cass_cluster_set_max_concurrent_requests_threshold (default 100). You can set higher value with cass_cluster_set_core_connections_per_host if you know that you'll generate the big number of in-flight request from the beginning - in this case you won't spend time opening an additional connection when you're executing requests.

Upvotes: 3

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