anchor.diff:   * Add x-opaque-id to search slow logs {pull}31539[#31539] (issue: {issue}31521[#31521])
   
   Machine learning::
  -* If a {ml} datafeed is configured to use cross cluster search to retrieve data, 
  -the remote clusters must have {xpack} installed and a valid licence for {ml}. 
  -If the licence requirements are not met, datafeeds using cross cluster search 
  +* If a {ml} datafeed is configured to use cross cluster search to retrieve data,
  +the remote clusters must have {xpack} installed and a valid licence for {ml}.
  +If the licence requirements are not met, datafeeds using cross cluster search
   will not start. {pull}31247[#31247]
    * Use default request durability for .ml-state index {pull}32233[#32233]
    * Return statistics about forecasts as part of the job stats and usage API {pull}31647[#31647] (issue: {issue}31395[#31395])
  
positive.code: * Rate limit established model memory updates {pull}31768[#31768]
  * Account for gaps in data counts after job is reopened {pull}30294[#30294] (issue: {issue}30080[#30080])
  * Ages seasonal components in proportion to the fraction of values with which they're updated ({ml-pull}88[#88] (issue: {ml-issue}87[#87]))
  * Fixes persist and restore, which were missing some of the trend model state. 
  ({ml-pull}103[#103], {ml-pull}99[#99])
  * Stops zero variance data from generating a log error in the forecast confidence interval calculation ({ml-pull}120[#120], {ml-pull}107[#107])
  * Fixes corner case which was failing to calculate lgamma values and fixes the 
  corresponding log errors ({ml-pull}131[#131], {ml-pull}126[#126])
  * Fixes influence count per bucket for metric population analyses, which was 
  wrong and lead to incorrect influencer scoring ({ml-pull}153[#153], {ml-pull}150[#150])
  * Fixes a possible SIGSEGV for jobs with multivariate by fields enabled, which caused the jobs to fail ({ml-pull}174[#174], {ml-pull}170[#170])
  * Corrects the model bounds and typical value calculation for time series models 
  which use a multimodal distribution. This issue could cause "Unable to bracket 
  left percentile =..." errors to appear in the logs. ({ml-pull}178[#178], {ml-pull}176[#176])
  
  Mapping::
  
negative.code: [[release-notes-6.4.2]]
  == {es} version 6.4.2
  
  [[enhancement-6.4.2]]
  [float]
  === Enhancements
  
  Search::
  * Add a limit for graph phrase query expansion {pull}34031[#34031]
  
  [[bug-6.4.2]]
  [float]
  === Bug fixes
  
  Core::
  * Fix AutoQueueAdjustingExecutorBuilder settings validation {pull}33922[#33922]
  
  Index APIs::
  * Allow to clear the fielddata cache per field {pull}33807[#33807] (issue: {issue}33798[#33798])
  
  Network::
  *  Support PKCS#11 tokens as keystores and truststores  [OPEN] {pull}34063[#34063] (issue: {issue}11[#11])
  * Correctly handle PKCS#11 tokens for system keystore {pull}33460[#33460] (issues: {issue}11[#11], {issue}33459[#33459])
  
  Security::
  * Security: use default scroll keepalive {pull}33639[#33639]
  
  Snapshot/Restore::
  * Do not override named S3 client credentials {pull}33793[#33793] (issue: {issue}33769[#33769])
  
  Watcher::
  * Watcher: Ensure triggered watch deletion is sync {pull}33799[#33799]
  
  [[release-notes-6.4.1]]
  == {es} version 6.4.1
  