Second similar error today. This is also the first time I've seen this error.
To avoid creating high replication lag, this transaction was aborted because the write duration (3.068653345108) exceeded the 3 second limit. If you are changing many items at once, try doing multiple smaller operations instead.
[XReuagpAMFgAAILDXVcAAAAJ] 2019-06-29 18:31:14: Fatal exception of type "Wikimedia\Rdbms\DBTransactionSizeError"
exception.file /srv/mediawiki/php-1.34.0-wmf.11/includes/libs/rdbms/loadbalancer/LoadBalancer.php:1462 exception.message Transaction spent 3.068653345108 second(s) in writes, exceeding the limit of 3 exception.trace #0 /srv/mediawiki/php-1.34.0-wmf.11/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1910): Closure$Wikimedia\Rdbms\LoadBalancer::approveMasterChanges(Wikimedia\Rdbms\DatabaseMysqli) #1 /srv/mediawiki/php-1.34.0-wmf.11/includes/libs/rdbms/loadbalancer/LoadBalancer.php(1472): Wikimedia\Rdbms\LoadBalancer->forEachOpenMasterConnection(Closure$Wikimedia\Rdbms\LoadBalancer::approveMasterChanges;482) #2 /srv/mediawiki/php-1.34.0-wmf.11/includes/libs/rdbms/lbfactory/LBFactory.php(230): Wikimedia\Rdbms\LoadBalancer->approveMasterChanges(array, string, integer) #3 /srv/mediawiki/php-1.34.0-wmf.11/includes/libs/rdbms/lbfactory/LBFactoryMulti.php(401): Closure$Wikimedia\Rdbms\LBFactory::forEachLBCallMethod(Wikimedia\Rdbms\LoadBalancer, string, array) #4 /srv/mediawiki/php-1.34.0-wmf.11/includes/libs/rdbms/lbfactory/LBFactory.php(233): Wikimedia\Rdbms\LBFactoryMulti->forEachLB(Closure$Wikimedia\Rdbms\LBFactory::forEachLBCallMethod;195, array) #5 /srv/mediawiki/php-1.34.0-wmf.11/includes/libs/rdbms/lbfactory/LBFactory.php(281): Wikimedia\Rdbms\LBFactory->forEachLBCallMethod(string, array) #6 /srv/mediawiki/php-1.34.0-wmf.11/includes/MediaWiki.php(596): Wikimedia\Rdbms\LBFactory->commitMasterChanges(string, array) #7 /srv/mediawiki/php-1.34.0-wmf.11/includes/MediaWiki.php(566): MediaWiki::preOutputCommit(RequestContext, Closure$MediaWiki::main;391) #8 /srv/mediawiki/php-1.34.0-wmf.11/includes/MediaWiki.php(900): MediaWiki->doPreOutputCommit(Closure$MediaWiki::main;391) #9 /srv/mediawiki/php-1.34.0-wmf.11/includes/MediaWiki.php(515): MediaWiki->main() #10 /srv/mediawiki/php-1.34.0-wmf.11/index.php(42): MediaWiki->run() #11 /srv/mediawiki/w/index.php(3): include(string) #12 {main}