High fragment blocked time indicates data transfer bottleneck

Query fragments show high blocked time waiting for data transfer between fragments. Fragment execution stalls while waiting for input from RemoteSource operations. Example: Fragment blocked 1.80s with 933.53ms spent waiting on input.

Investigate network throughput between workers using network exchange metrics. Check worker distribution and data locality. Consider adjusting query parallelism, reviewing partitioning strategy to reduce data shuffling, or increasing network bandwidth between workers.