Trending in fatalmonitor since 1.27.0-wmf.11 hit the test wikis today.
```
{
"_index": "logstash-2016.01.20",
"_type": "mediawiki",
"_id": "AVJclfvzlAIL90Zztzzb",
"_score": null,
"_source": {
"message": "Can neither load the session nor create an empty session",
"@version": 1,
"@timestamp": "2016-01-20T01:11:19.000Z",
"type": "mediawiki",
"host": "mw1218",
"level": "ERROR",
"tags": [
"syslog",
"es",
"es",
"exception-json",
"normalized_message_untrimmed"
],
"channel": "exception",
"url": "/w/index.php?title=MediaWiki:Gadget-DotsSyntaxHighlighter.js&action=raw&ctype=text/javascript&smaxage=21600&maxage=86400",
"ip": "xxx.xxx.xxx.xxx",
"http_method": "GET",
"server": "www.mediawiki.org",
"referrer": "https://es.wikipedia.org/wiki/Nuevas_siete_maravillas_del_mundo_moderno",
"uid": "097c74e",
"process_id": 29748,
"wiki": "mediawikiwiki",
"private": true,
"file": "/srv/mediawiki/php-1.27.0-wmf.11/includes/session/SessionManager.php",
"line": 232,
"code": 0,
"backtrace": [
{
"file": "/srv/mediawiki/php-1.27.0-wmf.11/includes/session/PHPSessionHandler.php",
"line": 239,
"function": "getSessionById",
"class": "MediaWiki\\Session\\SessionManager",
"type": "->",
"args": [
"string"
]
},
{
"function": "write",
"class": "MediaWiki\\Session\\PHPSessionHandler",
"type": "->",
"args": [
"string",
"string"
]
},
{
"function": "call_user_func",
"args": [
"array",
"string",
"string"
]
},
{
"function": "write",
"class": "__SystemLib\\SessionForwardingHandler",
"type": "->",
"args": [
"string",
"string"
]
},
{
"file": "/srv/mediawiki/php-1.27.0-wmf.11/includes/session/SessionManager.php",
"line": 592,
"function": "session_write_close",
"args": []
},
{
"function": "shutdown",
"class": "MediaWiki\\Session\\SessionManager",
"type": "->",
"args": []
}
],
"previous": {
"id": "8da7669b",
"type": "InvalidArgumentException",
"file": "/srv/mediawiki/php-1.27.0-wmf.11/includes/session/SessionManager.php",
"line": 257,
"message": "Session ID already exists",
"code": 0,
"url": "/w/index.php?title=MediaWiki:Gadget-DotsSyntaxHighlighter.js&action=raw&ctype=text/javascript&smaxage=21600&maxage=86400",
"backtrace": [
{
"file": "/srv/mediawiki/php-1.27.0-wmf.11/includes/session/SessionManager.php",
"line": 223,
"function": "getEmptySessionInternal",
"class": "MediaWiki\\Session\\SessionManager",
"type": "->",
"args": [
"FauxRequest",
"string"
]
},
{
"file": "/srv/mediawiki/php-1.27.0-wmf.11/includes/session/PHPSessionHandler.php",
"line": 239,
"function": "getSessionById",
"class": "MediaWiki\\Session\\SessionManager",
"type": "->",
"args": [
"string"
]
},
{
"function": "write",
"class": "MediaWiki\\Session\\PHPSessionHandler",
"type": "->",
"args": [
"string",
"string"
]
},
{
"function": "call_user_func",
"args": [
"array",
"string",
"string"
]
},
{
"function": "write",
"class": "__SystemLib\\SessionForwardingHandler",
"type": "->",
"args": [
"string",
"string"
]
},
{
"file": "/srv/mediawiki/php-1.27.0-wmf.11/includes/session/SessionManager.php",
"line": 592,
"function": "session_write_close",
"args": []
},
{
"function": "shutdown",
"class": "MediaWiki\\Session\\SessionManager",
"type": "->",
"args": []
}
]
},
"exception_id": "d39bb4a2",
"class": "mediawiki",
"message_checksum": "e9ca78920ae33253dffd58a42c18f46e",
"normalized_message": "Can neither load the session nor create an empty session"
},
"sort": [
1453252279000
]
}
```
All of them seem to have `Session ID already exists` as the previous Exception which sounds like a race condition in the new session storage layer.