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dead_blobs_* MergeTree table settings

These settings are available in system.merge_tree_settings and are autogenerated from ClickHouse source.

dead_blobs_to_delay_insert

Type
UInt64
Default
100000
Version history
VersionDefault valueComment
26.7100000New setting to artificially slow down inserts when the dead blobs queues of the table's disks accumulate too many blobs pending removal.

If the number of blobs pending removal in the dead blobs queues of the table’s disks exceeds the dead_blobs_to_delay_insert value, an INSERT is artificially slowed down (up to max_delay_to_insert).

The dead blobs queue belongs to the disk and is shared by all tables on it (including blobs of already dropped tables), so size the threshold for the whole disk rather than a single table.

Possible values:

  • Any positive integer.
  • 0 — disabled.

dead_blobs_to_throw_insert

Type
UInt64
Default
1000000
Version history
VersionDefault valueComment
26.71000000New setting to reject inserts when the dead blobs queues of the table's disks accumulate too many blobs pending removal.

If the number of blobs pending removal in the dead blobs queues of the table’s disks is more than the dead_blobs_to_throw_insert value, INSERT is interrupted with the following error:

“Too many dead blobs in queue (N) on disks of table. Blobs cleanup is processing significantly slower than inserts”

The dead blobs queue belongs to the disk and is shared by all tables on it (including blobs of already dropped tables), so size the threshold for the whole disk rather than a single table.

Possible values:

  • Any positive integer.
  • 0 — disabled.
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