HBaseTimelineWriterImpl sync writes has to avoid thread blocking if storage is down. Currently we check if hbase storage is down in TimelineReader before reading entities and fail immediately in YARN-8302. Similar fix is needed for write. Async is handled in YARN-9335.
YARN-9335[atsv2] Restrict the number of elements held in timeline collector when backend is unreachable for async calls
YARN-8302ATS v2 should handle HBase connection issue properly