yugabyte/yugabyte-db

[DocDB] Add flag for configuring rocksdb bytes_per_sync option

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#10,822 opened on Dec 9, 2021

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area/docdbgood first issuekind/enhancementpriority/medium

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Description

Jira Link: DB-590

Description

  // Allows OS to incrementally sync files to disk while they are being
  // written, in the background. Issue one request for every bytes_per_sync
  // written. 0 turns it off.
  // Default: 0
  uint64_t bytes_per_sync = 0;

DBOptions SanitizeOptions(const std::string& dbname, const DBOptions& src) {
...
  if (result.rate_limiter.get() != nullptr) {
    if (result.bytes_per_sync == 0) {
      result.bytes_per_sync = 1024 * 1024;
    }
  }
...

Currently, we don't set bytes_per_sync explicitly, but we use a rate limiter, so it leads to sync every 1MB (independently for each file) at rocksdb level.

Contributor guide

Research direction
Examine the DBOptions sanitization logic and understand how existing flags are exposed. Then add a new gflag for bytes per sync and integrate it into the sanitization function.
Tech stack
cpp
Domain
databasebackend
Issue type
Feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
Half day
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C++rocksdbGit
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60