From: Aaron Schulz <aschulz@wikimedia.org>
Date: Wed, 12 Apr 2017 23:17:00 +0000 (-0700)
Subject: Add comments to ApiBase::isWriteMode()
X-Git-Tag: 1.31.0-rc.0~3519^2
X-Git-Url: http://git.cyclocoop.org/%24image?a=commitdiff_plain;h=be4065c55f355d757761e207833f8f765f99f8e7;p=lhc%2Fweb%2Fwiklou.git

Add comments to ApiBase::isWriteMode()

Change-Id: I3581f5e3055c425367d265a5c57831bb34dd5a2f
---

diff --git a/includes/api/ApiBase.php b/includes/api/ApiBase.php
index b698ceffbc..37750c82e8 100644
--- a/includes/api/ApiBase.php
+++ b/includes/api/ApiBase.php
@@ -385,6 +385,13 @@ abstract class ApiBase extends ContextSource {
 
 	/**
 	 * Indicates whether this module requires write mode
+	 *
+	 * This should return true for modules that may require synchronous database writes.
+	 * Modules that do not need such writes should also not rely on master database access,
+	 * since only read queries are needed and each master DB is a single point of failure.
+	 * Additionally, requests that only need replica DBs can be efficiently routed to any
+	 * datacenter via the Promise-Non-Write-API-Action header.
+	 *
 	 * @return bool
 	 */
 	public function isWriteMode() {