X-Git-Url: http://git.heureux-cyclage.org/?a=blobdiff_plain;f=includes%2FDefaultSettings.php;h=3bfc8f8241e77e6d43135d786383154efbb8c479;hb=4f76b9543a8cec4358cfa15301d0bda38f1b4f26;hp=ce53060fbaae185627349a790de66939a7eba1b9;hpb=490e35598dfa406d9acd886b85e3ae7e9260e27e;p=lhc%2Fweb%2Fwiklou.git

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index ce53060fba..3bfc8f8241 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -1958,7 +1958,8 @@ $wgSearchTypeAlternatives = null;
 
 /**
  * Table name prefix.
- * This should be alphanumeric, contain neither spaces nor hyphens, and end in "_"
+ * Should be alphanumeric plus underscores, and not contain spaces nor hyphens.
+ * Suggested format ends with an underscore.
  */
 $wgDBprefix = '';
 
@@ -2415,11 +2416,11 @@ $wgObjectCaches = [
 		'class'       => ReplicatedBagOStuff::class,
 		'readFactory' => [
 			'class' => SqlBagOStuff::class,
-			'args'  => [ [ 'slaveOnly' => true ] ]
+			'args'  => [ [ 'replicaOnly' => true ] ]
 		],
 		'writeFactory' => [
 			'class' => SqlBagOStuff::class,
-			'args'  => [ [ 'slaveOnly' => false ] ]
+			'args'  => [ [ 'replicaOnly' => false ] ]
 		],
 		'loggroup'  => 'SQLBagOStuff',
 		'reportDupes' => false
@@ -2491,11 +2492,35 @@ $wgWANObjectCaches = [
 $wgEnableWANCacheReaper = false;
 
 /**
- * Main object stash type. This should be a fast storage system for storing
- * lightweight data like hit counters and user activity. Sites with multiple
- * data-centers should have this use a store that replicates all writes. The
- * store should have enough consistency for CAS operations to be usable.
- * Reads outside of those needed for merge() may be eventually consistent.
+ * The object store type of the main stash.
+ *
+ * This store should be a very fast storage system optimized for holding lightweight data
+ * like incrementable hit counters and current user activity. The store should replicate the
+ * dataset among all data-centers. Any add(), merge(), lock(), and unlock() operations should
+ * maintain "best effort" linearizability; as long as connectivity is strong, latency is low,
+ * and there is no eviction pressure prompted by low free space, those operations should be
+ * linearizable. In terms of PACELC (https://en.wikipedia.org/wiki/PACELC_theorem), the store
+ * should act as a PA/EL distributed system for these operations. One optimization for these
+ * operations is to route them to a "primary" data-center (e.g. one that serves HTTP POST) for
+ * synchronous execution and then replicate to the others asynchronously. This means that at
+ * least calls to these operations during HTTP POST requests would quickly return.
+ *
+ * All other operations, such as get(), set(), delete(), changeTTL(), incr(), and decr(),
+ * should be synchronous in the local data-center, replicating asynchronously to the others.
+ * This behavior can be overriden by the use of the WRITE_SYNC and READ_LATEST flags.
+ *
+ * The store should *preferably* have eventual consistency to handle network partitions.
+ *
+ * Modules that rely on the stash should be prepared for:
+ *   - add(), merge(), lock(), and unlock() to be slower than other write operations,
+ *     at least in "secondary" data-centers (e.g. one that only serves HTTP GET/HEAD)
+ *   - Other write operations to have race conditions accross data-centers
+ *   - Read operations to have race conditions accross data-centers
+ *   - Consistency to be either eventual (with Last-Write-Wins) or just "best effort"
+ *
+ * In general, this means avoiding updates during idempotent HTTP requests (GET/HEAD) and
+ * avoiding assumptions of true linearizability (e.g. accepting anomalies). Modules that need
+ * these kind of guarantees should use other storage mediums.
  *
  * The options are:
  *   - db:      Store cache objects in the DB
@@ -3252,33 +3277,6 @@ $wgOverrideUcfirstCharacters = [];
  */
 $wgMimeType = 'text/html';
 
-/**
- * Previously used as content type in HTML script tags. This is now ignored since
- * HTML5 doesn't require a MIME type for script tags (javascript is the default).
- * It was also previously used by RawAction to determine the ctype query parameter
- * value that will result in a javascript response.
- * @deprecated since 1.22
- */
-$wgJsMimeType = null;
-
-/**
- * The default xmlns attribute. The option to define this has been removed.
- * The value of this variable is no longer used by core and is set to a fixed
- * value in Setup.php for compatibility with extensions that depend on the value
- * of this variable being set. Such a dependency however is deprecated.
- * @deprecated since 1.22
- */
-$wgXhtmlDefaultNamespace = null;
-
-/**
- * Previously used to determine if we should output an HTML5 doctype.
- * This is no longer used as we always output HTML5 now. For compatibility with
- * extensions that still check the value of this config it's value is now forced
- * to true by Setup.php.
- * @deprecated since 1.22
- */
-$wgHtml5 = true;
-
 /**
  * Defines the value of the version attribute in the <html> tag, if any.
  *
@@ -6305,11 +6303,6 @@ $wgShowDebug = false;
  */
 $wgDebugTimestamps = false;
 
-/**
- * Print HTTP headers for every request in the debug information.
- */
-$wgDebugPrintHttpHeaders = true;
-
 /**
  * Show the contents of $wgHooks in Special:Version
  */
@@ -6498,14 +6491,6 @@ $wgStatsdSamplingRates = [
  */
 $wgPageInfoTransclusionLimit = 50;
 
-/**
- * Set this to an integer to only do synchronous site_stats updates
- * one every *this many* updates. The other requests go into pending
- * delta values in $wgMemc. Make sure that $wgMemc is a global cache.
- * If set to -1, updates *only* go to $wgMemc (useful for daemons).
- */
-$wgSiteStatsAsyncFactor = false;
-
 /**
  * Parser test suite files to be run by parserTests.php when no specific
  * filename is passed to it.