Hi, I want to suggest the change[1] of the thread pool type in BigQuery streaming insert for Java SDK (BEAM-6443). When we insert small data into BigQuery very fast by using BigQueryIO.write, it generates lots of rate limit exceeded errors in a log file. It's mainly because the number of threads to be used for the inserting job is just too large (50 shards * dozens of futures executed by unlimited thread pool per each bundle). I've conducted some benchmarks[2] and could see that the change from unlimited thread pool to single thread pool reduces the number of (same repeated, possibly meaningless) error messages by 1/4 while retaining the same performance. I think that this change will not break any important performance measure but if anybody has any concerns about this change please let me know.
Thanks, [1] https://github.com/apache/beam/pull/7547 [2] https://docs.google.com/document/d/1EhRNWLevm86GD_QtvlrTauHITVMwQBzuemyp-w4Z_ck/edit#heading=h.c0angyd9tn21
