Too many alloc/memcpy in V2Batch

[fbacchella]

See

logstash-input-beats/src/main/java/org/logstash/beats/V2Batch.java

Line 84 in 5813c67

internalBuffer.capacity(internalBuffer.capacity() + size + (2 * SIZE_OF_INT));

It calls internalBuffer.capacity(...) for each message append in the batch. Internally, it probably uses an allocation and a memcopy. It should try to anticipate more events to come.

For example, ArrayList uses:
int newCapacity = oldCapacity + (oldCapacity >> 1);

Or it could be smarter and try to guess a possible maximum size.

[PriestTomb]

I also encountered this problem, I used Filebeat to collect log data, and then sent to Logstash, each time sending 2048 messages, a total of 100MB size, logstash-input-beats will reallocated 2048 times, which will lead to more and more time-consuming.