I had this same issue and it turned out to be an improper usage of an java API. I was initializing a builder in a batch processing method that was that not supposed to be initiallized more than once.
Basically I was doing something like:
for (batch in batches) {
process_batch(batch)
}
def process_batch(batch) {
var client = TransportClient.builder().build()
client.processList(batch)
}
when I should have done this:
for (batch in batches) {
var client = TransportClient.builder().build()
process_batch(batch, client)
}
def process_batch(batch, client) {
client.processList(batch)
}