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7bf1d8c5c0
Add config for eager / lazy connection initialization in ResourcePool Description Currently, when multiple tasks are launched, each of them eagerly initializes a full pool's worth of connections to the coordinator. While this is acceptable when the parameter for number of eagerConnections (== maxSize) is small, this can be problematic in environments where it's a large value (say 1000) and multiple tasks are launched simultaneously, which can cause a large number of connections to be created to the coordinator, thereby overwhelming it. Patch Nodes like the broker may require eager initialization of resources and do not create connections with the Coordinator. It is unnecessary to do this with other types of nodes. A config parameter eagerInitialization is added, which when set to true, initializes the max permissible connections when ResourcePool is initialized. If set to false, lazy initialization of connection resources takes place. NOTE: All nodes except the broker have this new parameter set to false in the quickstart as part of this PR Algorithm The current implementation relies on the creation of maxSize resources eagerly. The new implementation's behaviour is as follows: If a resource has been previously created and is available, lend it. Else if the number of created resources is less than the allowed parameter, create and lend it. Else, wait for one of the lent resources to be returned. |
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