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system.crash_log

Querying in ClickHouse Cloud

The data in this system table is held locally on each node in ClickHouse Cloud. Obtaining a complete view of all data, therefore, requires the clusterAllReplicas function. See here for further details.

Description​

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)) — The hostname where the crash occurred.
  • event_date (Date) — The date of the crash.
  • event_time (DateTime) — The time of the crash.
  • timestamp_ns (UInt64) — Timestamp of the event with nanoseconds.
  • signal (Int32) — Signal number.
  • signal_code (Int32) — Signal code. Provides additional context about the signal cause.
  • thread_id (UInt64) — Thread ID.
  • query_id (String) — Query ID.
  • query (String) — Query text that was being executed when the crash occurred.
  • 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.
  • fault_address (Nullable(UInt64)) — Memory address that caused the fault.
  • fault_access_type (String) — Type of memory access that caused the fault (e.g., 'read', 'write').
  • signal_description (String) — Human-readable description based on signal_code (e.g., 'Address not mapped to object').
  • current_exception_trace_full (Array(String)) — Current exception stack trace with symbolized frames (std::terminate crashes only).
  • version (String) — ClickHouse server version.
  • revision (UInt32) — ClickHouse server revision.
  • build_id (String) — BuildID that is generated by compiler.
  • git_hash (String) — Git commit hash of the ClickHouse source code.
  • architecture (String) — CPU architecture (e.g., x86_64, aarch64).

Example​

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

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​