Here's what logstash looks like at the time of writing:
That's a ton of noise about redis timeouts. Way too much. The pairs of 473, 32, and 21 are from this (it emits two error logs for each timeout). That's 1052 errors in the past hour, just in the first page of fatals (there's one more in the next page of fatals).
All of the form:
Warning: Failed connecting to redis server at {redis_server}.eqiad.wmnet: Connection timed out in /srv/mediawiki/php-1.28.0-wmf.{XX}/includes/libs/redis/RedisConnectionPool.php on line 235