memory_profiler_* session settings

These settings are available in system.settings and are autogenerated from the ClickHouse snapshot.

memory_profiler_sample_max_allocation_size

Collect random allocations of size less or equal than the specified value with probability equal to memory_profiler_sample_probability. 0 means disabled. You may want to set ‘max_untracked_memory’ to 0 to make this threshold work as expected.

memory_profiler_sample_min_allocation_size

Collect random allocations of size greater or equal than the specified value with probability equal to memory_profiler_sample_probability. 0 means disabled. You may want to set ‘max_untracked_memory’ to 0 to make this threshold work as expected.

memory_profiler_sample_probability

Collect random allocations and deallocations and write them into system.trace_log with ‘MemorySample’ trace_type. The probability is for every alloc/free regardless of the size of the allocation (can be changed with memory_profiler_sample_min_allocation_size and memory_profiler_sample_max_allocation_size). Note that sampling happens only when the amount of untracked memory exceeds ‘max_untracked_memory’. You may want to set ‘max_untracked_memory’ to 0 for extra fine-grained sampling.

memory_profiler_step

Sets the step of memory profiler. Whenever query memory usage becomes larger than every next step in number of bytes the memory profiler will collect the allocating stacktrace and will write it into trace_log.

Possible values:

• A positive integer number of bytes.

• 0 for turning off the memory profiler.