(kvrocks) branch unstable updated: Enable rocksdb read option `avoid_unnecessary_blocking_io` to avoid unexpected long latency (#1903)

[hulk]

This is an automated email from the ASF dual-hosted git repository.

hulk pushed a commit to branch unstable
in repository https://gitbox.apache.org/repos/asf/kvrocks.git


The following commit(s) were added to refs/heads/unstable by this push:
     new 2b9faf78 Enable rocksdb read option `avoid_unnecessary_blocking_io` to 
avoid unexpected long latency (#1903)
2b9faf78 is described below

commit 2b9faf782fbfff4d6dab091540101c678546b146
Author: Ted Mostly <wanghens...@qq.com>
AuthorDate: Wed Nov 22 23:54:57 2023 +0800

    Enable rocksdb read option `avoid_unnecessary_blocking_io` to avoid 
unexpected long latency (#1903)
    
    Co-authored-by: hulk <hulk.webs...@gmail.com>
---
 kvrocks.conf           | 7 +++++++
 src/config/config.cc   | 1 +
 src/config/config.h    | 1 +
 src/storage/storage.cc | 3 +++
 4 files changed, 12 insertions(+)

diff --git a/kvrocks.conf b/kvrocks.conf
index fa36d96a..e5460187 100644
--- a/kvrocks.conf
+++ b/kvrocks.conf
@@ -863,5 +863,12 @@ rocksdb.write_options.memtable_insert_hint_per_batch no
 # Default: yes
 rocksdb.rate_limiter_auto_tuned yes
 
+# Enable this option will schedule the deletion of obsolete files in a 
background thread 
+# on iterator destruction. It can reduce the latency if there are many files 
to be removed.
+# see https://github.com/facebook/rocksdb/wiki/IO#avoid-blocking-io 
+#
+# Default: yes
+# rocksdb.avoid_unnecessary_blocking_io yes
+
 ################################ NAMESPACE 
#####################################
 # namespace.test change.me
diff --git a/src/config/config.cc b/src/config/config.cc
index f9cf8cf6..c71103b7 100644
--- a/src/config/config.cc
+++ b/src/config/config.cc
@@ -216,6 +216,7 @@ Config::Config() {
        new YesNoField(&rocks_db.level_compaction_dynamic_level_bytes, false)},
       {"rocksdb.max_background_jobs", false, new 
IntField(&rocks_db.max_background_jobs, 4, 0, 32)},
       {"rocksdb.rate_limiter_auto_tuned", true, new 
YesNoField(&rocks_db.rate_limiter_auto_tuned, true)},
+      {"rocksdb.avoid_unnecessary_blocking_io", true, new 
YesNoField(&rocks_db.avoid_unnecessary_blocking_io, true)},
 
       /* rocksdb write options */
       {"rocksdb.write_options.sync", true, new 
YesNoField(&rocks_db.write_options.sync, false)},
diff --git a/src/config/config.h b/src/config/config.h
index d3dc1442..244f1469 100644
--- a/src/config/config.h
+++ b/src/config/config.h
@@ -201,6 +201,7 @@ struct Config {
     bool level_compaction_dynamic_level_bytes;
     int max_background_jobs;
     bool rate_limiter_auto_tuned;
+    bool avoid_unnecessary_blocking_io = true;
 
     struct WriteOptions {
       bool sync;
diff --git a/src/storage/storage.cc b/src/storage/storage.cc
index 9c5d03af..77d0ab27 100644
--- a/src/storage/storage.cc
+++ b/src/storage/storage.cc
@@ -186,6 +186,9 @@ rocksdb::Options Storage::InitRocksDBOptions() {
   options.level_compaction_dynamic_level_bytes = 
config_->rocks_db.level_compaction_dynamic_level_bytes;
   options.max_background_jobs = config_->rocks_db.max_background_jobs;
 
+  // avoid blocking io on iteration
+  // see https://github.com/facebook/rocksdb/wiki/IO#avoid-blocking-io
+  options.avoid_unnecessary_blocking_io = 
config_->rocks_db.avoid_unnecessary_blocking_io;
   return options;
 }