anchor.diff:  * Do not cache term queries. {pull}21566[#21566] (issues: {issue}16031[#16031], {issue}20116[#20116])
   * Parse alias filters on the coordinating node {pull}20916[#20916]
   
  -Circuit Breakers::
  -* Cluster Settings Updates should not trigger circuit breakers. {pull}20827[#20827]
  -
   Cluster::
   * Cache successful shard deletion checks {pull}21438[#21438]
  -* Skip shard management code when updating cluster state on client/tribe nodes {pull}20731[#20731]
  -* Add clusterUUID to RestMainAction output {pull}20503[#20503]
   
   Core::
   * Reduce memory pressure when sending large terms queries. {pull}21776[#21776]
  
positive.code: * Remove `IndexTemplateAlreadyExistsException` and `IndexShardAlreadyExistsException` {pull}21539[#21539] (issue: {issue}21494[#21494])
  * Replace IndexAlreadyExistsException with ResourceAlreadyExistsException {pull}21494[#21494]
  
  Internal::
  * `_flush` should block by default {pull}20597[#20597] (issue: {issue}20569[#20569])
  
  Packaging::
  * Rename service.bat to elasticsearch-service.bat {pull}20496[#20496] (issue: {issue}17528[#17528])
  
  Plugin Lang Painless::
  * Remove all date 'now' methods from Painless {pull}20766[#20766] (issue: {issue}20762[#20762])
  
  REST::
  * Remove lenient stats parsing 5.x {pull}21576[#21576] (issues: {issue}20722[#20722], {issue}21410[#21410], {issue}21417[#21417])
  * Change separator for shards preference {pull}20786[#20786] (issues: {issue}20722[#20722], {issue}20769[#20769])
  
  
  
  [[breaking-java-5.1.1]]
  [float]
  === Breaking Java changes
  
  Core::
  * Remove ability to plug-in TransportService {pull}20505[#20505]
  
  Exceptions::
  * Backport: Replace IndexAlreadyExistsException with ResourceAlreadyExistsException {pull}21601[#21601] (issue: {issue}21494[#21494])
  
  Internal::
  * Pass executor name to request interceptor to support async intercept calls {pull}21089[#21089]
  * Remove TransportService#registerRequestHandler leniency {pull}20469[#20469] (issue: {issue}20468[#20468])
  
  Network::
  * Unguice Transport and friends {pull}20526[#20526]
  
  Plugins::
  * Plugins: Remove support for onModule {pull}21416[#21416]
  * Cleanup sub fetch phase extension point {pull}20382[#20382]
  
  
  
  
negative.code: [[release-notes-5.1.1]]
  == 5.1.1 Release Notes
  
  [[breaking-5.1.1]]
  [float]
  === Breaking changes
  
  Aliases::
  * Validate alias names the same as index names {pull}20771[#20771] (issue: {issue}20748[#20748])
  
  Discovery::
  * Remove pluggability of ElectMasterService {pull}21031[#21031]
  