ClickHouse/docs/en/operations/system-tables/crash-log.md

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/en/operations/system-tables/crash-log

crash_log

Contains information about stack traces for fatal errors. The table does not exist in the database by default, it is created only when fatal errors occur.

Columns:

• hostname (LowCardinality(String)) — Hostname of the server executing the query.
• event_date (DateTime) — Date of the event.
• event_time (DateTime) — Time of the event.
• timestamp_ns (UInt64) — Timestamp of the event with nanoseconds.
• signal (Int32) — Signal number.
• thread_id (UInt64) — Thread ID.
• query_id (String) — Query ID.
• trace (Array(UInt64)) — Stack trace at the moment of crash. Each element is a virtual memory address inside ClickHouse server process.
• trace_full (Array(String)) — Stack trace at the moment of crash. Each element contains a called method inside ClickHouse server process.
• version (String) — ClickHouse server version.
• revision (UInt32) — ClickHouse server revision.
• build_id (String) — BuildID that is generated by compiler.

Example

Query:

SELECT * FROM system.crash_log ORDER BY event_time DESC LIMIT 1;

Result (not full):

Row 1:
──────
hostname:     clickhouse.eu-central1.internal
event_date:   2020-10-14
event_time:   2020-10-14 15:47:40
timestamp_ns: 1602679660271312710
signal:       11
thread_id:    23624
query_id:     428aab7c-8f5c-44e9-9607-d16b44467e69
trace:        [188531193,...]
trace_full:   ['3. DB::(anonymous namespace)::FunctionFormatReadableTimeDelta::executeImpl(std::__1::vector<DB::ColumnWithTypeAndName, std::__1::allocator<DB::ColumnWithTypeAndName> >&, std::__1::vector<unsigned long, std::__1::allocator<unsigned long> > const&, unsigned long, unsigned long) const @ 0xb3cc1f9 in /home/username/work/ClickHouse/build/programs/clickhouse',...]
version:      ClickHouse 20.11.1.1
revision:     54442
build_id:

See also

• trace_log system table

Original article