From: Brian Wolff <bawolff+wn@gmail.com>
Date: Tue, 10 May 2016 19:38:27 +0000 (-0400)
Subject: use slave for row estimate in updateCollation.php
X-Git-Tag: 1.31.0-rc.0~7020^2
X-Git-Url: http://git.cyclocoop.org/%22%20.%20generer_url_aide%28?a=commitdiff_plain;h=09205b2954d00a122de74e3480c61e5b4242b6bf;p=lhc%2Fweb%2Fwiklou.git

use slave for row estimate in updateCollation.php

jcrespo reported a lag spike at the very beginning of running this
script. I'm guessing that's due to counting how many rows in
categorylinks to give the progress bar. Since we only need a
rough estimate for the progress meter, make that query run on
a slave. Also add a wfWaitForSlaves() immediately after it for
good measure.

Bug: T58041
Change-Id: I3cba392f0013fcb2ef86803632e2d9b1b88b3b29
---

diff --git a/maintenance/updateCollation.php b/maintenance/updateCollation.php
index 6d9a616077..dc9431f9d5 100644
--- a/maintenance/updateCollation.php
+++ b/maintenance/updateCollation.php
@@ -70,6 +70,7 @@ TEXT
 		global $wgCategoryCollation;
 
 		$dbw = $this->getDB( DB_MASTER );
+		$dbr = $this->getDB( DB_SLAVE );
 		$force = $this->getOption( 'force' );
 		$dryRun = $this->getOption( 'dry-run' );
 		$verboseStats = $this->getOption( 'verbose-stats' );
@@ -110,7 +111,7 @@ TEXT
 				];
 			}
 
-			$count = $dbw->estimateRowCount(
+			$count = $dbr->estimateRowCount(
 				'categorylinks',
 				'*',
 				$collationConds,
@@ -118,7 +119,7 @@ TEXT
 			);
 			// Improve estimate if feasible
 			if ( $count < 1000000 ) {
-				$count = $dbw->selectField(
+				$count = $dbr->selectField(
 					'categorylinks',
 					'COUNT(*)',
 					$collationConds,
@@ -131,6 +132,7 @@ TEXT
 				return;
 			}
 			$this->output( "Fixing collation for $count rows.\n" );
+			wfWaitForSlaves();
 		}
 		$count = 0;
 		$batchCount = 0;