2023-07-03 21:23:06 +00:00
|
|
|
---
|
|
|
|
|
slug: /en/operations/system-tables/jemalloc_bins
|
|
|
|
|
---
|
|
|
|
|
# jemalloc_bins
|
|
|
|
|
|
|
|
|
|
Contains information about memory allocations done via jemalloc allocator in different size classes (bins) aggregated from all arenas.
|
|
|
|
|
These statistics might not be absolutely accurate because of thread local caching in jemalloc.
|
|
|
|
|
|
|
|
|
|
Columns:
|
|
|
|
|
|
|
|
|
|
- `index` (UInt64) — Index of the bin ordered by size
|
|
|
|
|
- `large` (Bool) — True for large allocations and False for small
|
|
|
|
|
- `size` (UInt64) — Size of allocations in this bin
|
2023-07-06 07:09:55 +00:00
|
|
|
- `allocations` (UInt64) — Number of allocations
|
|
|
|
|
- `deallocations` (UInt64) — Number of deallocations
|
2023-07-03 21:23:06 +00:00
|
|
|
|
|
|
|
|
**Example**
|
|
|
|
|
|
|
|
|
|
Find the sizes of allocations that contributed the most to the current overall memory usage.
|
|
|
|
|
|
|
|
|
|
``` sql
|
|
|
|
|
SELECT
|
|
|
|
|
*,
|
2023-07-06 07:09:55 +00:00
|
|
|
allocations - deallocations AS active_allocations,
|
2023-07-03 21:23:06 +00:00
|
|
|
size * active_allocations AS allocated_bytes
|
|
|
|
|
FROM system.jemalloc_bins
|
|
|
|
|
WHERE allocated_bytes > 0
|
|
|
|
|
ORDER BY allocated_bytes DESC
|
|
|
|
|
LIMIT 10
|
|
|
|
|
```
|
|
|
|
|
|
|
|
|
|
``` text
|
2023-07-06 07:09:55 +00:00
|
|
|
┌─index─┬─large─┬─────size─┬─allocactions─┬─deallocations─┬─active_allocations─┬─allocated_bytes─┐
|
|
|
|
|
│ 82 │ 1 │ 50331648 │ 1 │ 0 │ 1 │ 50331648 │
|
|
|
|
|
│ 10 │ 0 │ 192 │ 512336 │ 370710 │ 141626 │ 27192192 │
|
|
|
|
|
│ 69 │ 1 │ 5242880 │ 6 │ 2 │ 4 │ 20971520 │
|
|
|
|
|
│ 3 │ 0 │ 48 │ 16938224 │ 16559484 │ 378740 │ 18179520 │
|
|
|
|
|
│ 28 │ 0 │ 4096 │ 122924 │ 119142 │ 3782 │ 15491072 │
|
|
|
|
|
│ 61 │ 1 │ 1310720 │ 44569 │ 44558 │ 11 │ 14417920 │
|
|
|
|
|
│ 39 │ 1 │ 28672 │ 1285 │ 913 │ 372 │ 10665984 │
|
|
|
|
|
│ 4 │ 0 │ 64 │ 2837225 │ 2680568 │ 156657 │ 10026048 │
|
|
|
|
|
│ 6 │ 0 │ 96 │ 2617803 │ 2531435 │ 86368 │ 8291328 │
|
|
|
|
|
│ 36 │ 1 │ 16384 │ 22431 │ 21970 │ 461 │ 7553024 │
|
|
|
|
|
└───────┴───────┴──────────┴──────────────┴───────────────┴────────────────────┴─────────────────┘
|
2023-07-03 21:23:06 +00:00
|
|
|
```
|
