Eugene Koifman created HIVE-14778: ------------------------------------- Summary: document threading model of Streaming API Key: HIVE-14778 URL: https://issues.apache.org/jira/browse/HIVE-14778 Project: Hive Issue Type: Bug Components: HCatalog, Transactions Affects Versions: 0.14.0 Reporter: Eugene Koifman Assignee: Eugene Koifman
The model is not obvious and needs to be documented properly. A StreamingConnection internally maintains 2 MetaStoreClient objects (each has 1 Thrift client for actual RPC). Let's call them "primary" and "heartbeat". Each TransactionBatch created from a given StreamingConnection, gets a reference to both of these MetaStoreClients. So the model is that there is at most 1 outstanding (not closed) TransactionBatch for any given StreamingConnection and for any given TransactionBatch there can be at most 2 threads accessing it concurrently. 1 thread calling TransactionBatch.heartbeat() (and nothing else) and the other calling all other methods. -- This message was sent by Atlassian JIRA (v6.3.4#6332)