Check flags when run Clickhouse

[patsevanton]

Hello!
I try run Clickhouse on old CPU, but get error:
Illegal instruction
I found Clickhouse required CPU flag SSE 4.2.
Can add check flags when run Clickhouse and echo "CPU doesnt support SSE 4.2" if CPU doesnt support SSE 4.2 ?
Thank you

[proller]

1. debian init script already prints this warning: https://github.com/yandex/ClickHouse/blob/master/debian/clickhouse-server.init#L51
2. you can recompile clickhouse on target host without sse4 usage.
   or you can use cmake flags:
   -DHAVE_SSE41=0 -DHAVE_SSE42=0 -DHAVE_POPCNT=0 DHAVE_PCLMULQDQ_INTRIN=0 -DPCLMULFLAG=' '

[patsevanton]

Thank for answer.
I use CentOS and systemd for run Clickhouse.
I think bad idea recompile clickhouse on target host without sse4
May be add CPU flag SSE 4.2 in binary ?

[blinkov]

At the moment there are no plans to support old CPUs in official ClickHouse builds.