#!/usr/bin/env bash # Tags: distributed CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd) # shellcheck source=../shell_config.sh . "$CURDIR"/../shell_config.sh # We check that even if max_threads is small, the setting max_distributed_connections # will allow to process queries on multiple shards concurrently. # We do sleep 1.5 seconds on ten machines. # If concurrency is one (bad) the query will take at least 15 seconds and the following loops are guaranteed to be infinite. # If concurrency is 10 (good), the query may take less than 10 second with non-zero probability # and the following loops will finish with probability 1 assuming independent random variables. while true; do timeout 10 ${CLICKHOUSE_CLIENT} --max_threads 1 --max_distributed_connections 10 --query " SELECT sleep(1.5) FROM remote('127.{1..10}', system.one) FORMAT Null" --prefer_localhost_replica=0 && break done while true; do timeout 10 ${CLICKHOUSE_CLIENT} --max_threads 1 --max_distributed_connections 10 --query " SELECT sleep(1.5) FROM remote('127.{1..10}', system.one) FORMAT Null" --prefer_localhost_replica=1 && break done # If max_distributed_connections is low and async_socket_for_remote is disabled, # the concurrency of distributed queries will be also low. timeout 1 ${CLICKHOUSE_CLIENT} --max_threads 1 --max_distributed_connections 1 --async_socket_for_remote 0 --query " SELECT sleep(0.15) FROM remote('127.{1..10}', system.one) FORMAT Null" --prefer_localhost_replica=0 && echo 'Fail' timeout 1 ${CLICKHOUSE_CLIENT} --max_threads 1 --max_distributed_connections 1 --async_socket_for_remote 0 --query " SELECT sleep(0.15) FROM remote('127.{1..10}', system.one) FORMAT Null" --prefer_localhost_replica=1 && echo 'Fail' echo 'Ok'