@@ -609,21 +609,21 @@ <h1>Compaction</h1>
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</ ul >
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< p >
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Other options impacting performance of compactions and when they get triggered
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- are:
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+ are:
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< ul >
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< p >
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- < li > < code > Options::access_hint_on_compaction_start</ code > - Specify the file access
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+ < li > < code > Options::access_hint_on_compaction_start</ code > - Specify the file access
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pattern once a compaction is started. It will be applied to all input files of a compaction. Default: NORMAL
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< p >
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- < li > < code > Options::level0_file_num_compaction_trigger</ code > - Number of files to trigger level-0 compaction.
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+ < li > < code > Options::level0_file_num_compaction_trigger</ code > - Number of files to trigger level-0 compaction.
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A negative value means that level-0 compaction will not be triggered by number of files at all.
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< p >
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< li > < code > Options::max_mem_compaction_level</ code > - Maximum level to which a new compacted memtable is pushed if it
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does not create overlap. We try to push to level 2 to avoid the relatively expensive level 0=> 1 compactions and to avoid some
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expensive manifest file operations. We do not push all the way to the largest level since that can generate a lot of wasted disk
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space if the same key space is being repeatedly overwritten.
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< p >
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- < li > < code > Options::target_file_size_base</ code > and < code > Options::target_file_size_multiplier</ code > -
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+ < li > < code > Options::target_file_size_base</ code > and < code > Options::target_file_size_multiplier</ code > -
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Target file size for compaction. target_file_size_base is per-file size for level-1.
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Target file size for level L can be calculated by target_file_size_base * (target_file_size_multiplier ^ (L-1))
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For example, if target_file_size_base is 2MB and target_file_size_multiplier is 10, then each file on level-1 will
@@ -698,7 +698,7 @@ <h1>Thread pools</h1>
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A thread pool is associated with Env environment object. The client has to create a thread pool by setting the number of background
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threads using method < code > Env::SetBackgroundThreads()</ code > defined in < code > rocksdb/env.h</ code > .
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We use the thread pool for compactions and memtable flushes.
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- Since memtable flushes are in critical code path (stalling memtable flush can stall writes, increasing p99), we suggest
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+ Since memtable flushes are in critical code path (stalling memtable flush can stall writes, increasing p99), we suggest
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having two thread pools - with priorities HIGH and LOW. Memtable flushes can be set up to be scheduled on HIGH thread pool.
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There are two options available for configuration of background compactions and flushes:
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< ul >
@@ -779,9 +779,9 @@ <h1>Statistics</h1>
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< p >
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To be able to efficiently tune your application, it is always helpful if you
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have access to usage statistics. You can collect those statistics by setting
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- < code > Options::table_stats_collectors </ code > or
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+ < code > Options::table_properties_collectors </ code > or
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< code > Options::statistics</ code > . For more information, refer to
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- < code > rocksdb/table_stats .h</ code > and < code > rocksdb/statistics.h</ code > .
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+ < code > rocksdb/table_properties .h</ code > and < code > rocksdb/statistics.h</ code > .
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These should not add significant overhead to your application and we
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recommend exporting them to other monitoring tools.
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