Deprecate not copy settings and explicitly disallow (#30404)

We want copying settings to be the default behavior. This commit
deprecates not copying settings, and disallows explicitly not copying
settings. This gives users a transition path to the future default
behavior.

Author: jasontedor

docs/CHANGELOG.asciidoc

@@ -163,7 +163,8 @@ analysis module.  ({pull}30397[#30397])
 [float]
 === Enhancements
 
-{ref-64}/breaking_64_api_changes.html#copy-source-settings-on-resize[Allow copying source settings on index resize operations] ({pull}30255[#30255])
+{ref-64}/breaking_64_api_changes.html#copy-source-settings-on-resize[Allow
+copying source settings on index resize operations] ({pull}30255[#30255], {pull}30404[#30404])
 
 Added new "Request" object flavored request methods in the RestClient. Prefer
 these instead of the multi-argument versions. ({pull}29623[#29623])

docs/reference/indices/shrink-index.asciidoc

@@ -62,11 +62,20 @@ the following request:
 
 [source,js]
 --------------------------------------------------
-POST my_source_index/_shrink/my_target_index
+POST my_source_index/_shrink/my_target_index?copy_settings=true
+{
+  "settings": {
+    "index.routing.allocation.require._name": null, <1>
+    "index.blocks.write": null <2>
+  }
+}
 --------------------------------------------------
 // CONSOLE
 // TEST[continued]
 
+<1> Clear the allocation requirement copied from the source index.
+<2> Clear the index write block copied from the source index.
+
 The above request returns immediately once the target index has been added to
 the cluster state -- it doesn't wait for the shrink operation to start.
 
@@ -97,7 +106,7 @@ and accepts `settings` and `aliases` parameters for the target index:
 
 [source,js]
 --------------------------------------------------
-POST my_source_index/_shrink/my_target_index
+POST my_source_index/_shrink/my_target_index?copy_settings=true
 {
   "settings": {
     "index.number_of_replicas": 1,
@@ -125,9 +134,11 @@ NOTE: By default, with the exception of `index.analysis`, `index.similarity`,
 and `index.sort` settings, index settings on the source index are not copied
 during a shrink operation. With the exception of non-copyable settings, settings
 from the source index can be copied to the target index by adding the URL
-parameter `copy_settings=true` to the request.
+parameter `copy_settings=true` to the request. Note that `copy_settings` can not
+be set to `false`. The parameter `copy_settings` will be removed in 9.0.0
 
-deprecated[6.4.0, `copy_settings` will default to `true` in 8.x and will be removed in 9.0.0]
+deprecated[6.4.0, not copying settings is deprecated, copying settings will be
+the default behavior in 8.x]
 
 [float]
 === Monitoring the shrink process

docs/reference/indices/split-index.asciidoc

@@ -123,7 +123,7 @@ the following request:
 
 [source,js]
 --------------------------------------------------
-POST my_source_index/_split/my_target_index
+POST my_source_index/_split/my_target_index?copy_settings=true
 {
   "settings": {
     "index.number_of_shards": 2
@@ -158,7 +158,7 @@ and accepts `settings` and `aliases` parameters for the target index:
 
 [source,js]
 --------------------------------------------------
-POST my_source_index/_split/my_target_index
+POST my_source_index/_split/my_target_index?copy_settings=true
 {
   "settings": {
     "index.number_of_shards": 5 <1>
@@ -181,9 +181,11 @@ NOTE: By default, with the exception of `index.analysis`, `index.similarity`,
 and `index.sort` settings, index settings on the source index are not copied
 during a split operation. With the exception of non-copyable settings, settings
 from the source index can be copied to the target index by adding the URL
-parameter `copy_settings=true` to the request.
+parameter `copy_settings=true` to the request. Note that `copy_settings` can not
+be set to `false`. The parameter `copy_settings` will be removed in 9.0.0
 
-deprecated[6.4.0, `copy_settings` will default to `true` in 8.x and will be removed in 9.0.0]
+deprecated[6.4.0, not copying settings is deprecated, copying settings will be
+the default behavior in 8.x]
 
 [float]
 === Monitoring the split process

rest-api-spec/src/main/resources/rest-api-spec/test/indices.shrink/10_basic.yml

@@ -1,5 +1,9 @@
 ---
 "Shrink index via API":
+  - skip:
+      version: " - 6.99.99"
+      reason: expects warnings that pre-7.0.0 will not send
+      features: "warnings"
   # creates an index with one document solely allocated on the master node
   # and shrinks it into a new index with a single shard
   # we don't do the relocation to a single node after the index is created
@@ -62,6 +66,8 @@
         body:
           settings:
             index.number_of_replicas: 0
+      warnings:
+        - "resize operations without copying settings is deprecated; set parameter [copy_settings] to [true] for future default behavior"
 
   - do:
       cluster.health:

rest-api-spec/src/main/resources/rest-api-spec/test/indices.shrink/20_source_mapping.yml

@@ -1,5 +1,10 @@
 ---
 "Shrink index ignores target template mapping":
+    - skip:
+        version: " - 6.99.99"
+        reason: expects warnings that pre-7.0.0 will not send
+        features: "warnings"
+
     - do:
         cluster.state: {}
         # Get master node id
@@ -65,6 +70,8 @@
           body:
             settings:
               index.number_of_replicas: 0
+        warnings:
+          - "resize operations without copying settings is deprecated; set parameter [copy_settings] to [true] for future default behavior"
 
     - do:
         cluster.health:

rest-api-spec/src/main/resources/rest-api-spec/test/indices.shrink/30_copy_settings.yml

@@ -1,8 +1,8 @@
 ---
 "Copy settings during shrink index":
   - skip:
-      version: " - 6.3.99"
-      reason:  copy_settings did not exist prior to 6.4.0
+      version: " - 6.99.99"
+      reason: expects warnings that pre-7.0.0 will not send
       features: "warnings"
 
   - do:
@@ -47,8 +47,6 @@
           settings:
             index.number_of_replicas: 0
             index.merge.scheduler.max_thread_count: 2
-      warnings:
-        - "parameter [copy_settings] is deprecated but was [true]"
 
   - do:
       cluster.health:
@@ -64,20 +62,19 @@
   - match: { copy-settings-target.settings.index.blocks.write: "true" }
   - match: { copy-settings-target.settings.index.routing.allocation.include._id: $master }
 
-  # now we do a actual shrink and do not copy settings
+  # now we do a actual shrink and do not copy settings (by default)
   - do:
       indices.shrink:
         index: "source"
         target: "no-copy-settings-target"
         wait_for_active_shards: 1
         master_timeout: 10s
-        copy_settings: false
         body:
           settings:
             index.number_of_replicas: 0
             index.merge.scheduler.max_thread_count: 2
       warnings:
-        - "parameter [copy_settings] is deprecated but was [false]"
+        - "resize operations without copying settings is deprecated; set parameter [copy_settings] to [true] for future default behavior"
 
   - do:
       cluster.health:
@@ -92,3 +89,16 @@
   - match: { no-copy-settings-target.settings.index.merge.scheduler.max_thread_count: "2" }
   - is_false: no-copy-settings-target.settings.index.blocks.write
   - is_false: no-copy-settings-target.settings.index.routing.allocation.include._id
+
+  # now we do a actual shrink and try to set no copy settings
+  - do:
+      catch: /illegal_argument_exception/
+      indices.shrink:
+        index: "source"
+        target: "explicit-no-copy-settings-target"
+        wait_for_active_shards: 1
+        master_timeout: 10s
+        copy_settings: false
+        body:
+          settings:
+            index.number_of_replicas: 0

rest-api-spec/src/main/resources/rest-api-spec/test/indices.split/10_basic.yml

@@ -33,8 +33,9 @@ setup:
 ---
 "Split index via API":
   - skip:
-      version: " - 6.0.99"
-      reason: Added in 6.1.0
+      version: " - 6.99.99"
+      reason: expects warnings that pre-7.0.0 will not send
+      features: "warnings"
 
   # make it read-only
   - do:
@@ -60,6 +61,8 @@ setup:
           settings:
             index.number_of_replicas: 0
             index.number_of_shards: 4
+      warnings:
+        - "resize operations without copying settings is deprecated; set parameter [copy_settings] to [true] for future default behavior"
 
   - do:
       cluster.health:
@@ -103,13 +106,13 @@ setup:
 
 ---
 "Split from 1 to N":
-#  - skip:
-#      version: " - 6.99.99"
-#      reason: Added in 7.0.0
-# uncomment once AwaitsFix is resolved
   - skip:
+      # when re-enabling uncomment the below skips
       version: "all"
       reason: "AwaitsFix'ing, see https://github.com/elastic/elasticsearch/issues/30503"
+      # version: " - 6.99.99"
+      # reason: expects warnings that pre-7.0.0 will not send
+      features: "warnings"
   - do:
       indices.create:
         index: source_one_shard
@@ -163,6 +166,8 @@ setup:
           settings:
             index.number_of_replicas: 0
             index.number_of_shards: 5
+      warnings:
+        - "resize operations without copying settings is deprecated; set parameter [copy_settings] to [true] for future default behavior"
 
   - do:
       cluster.health:
@@ -208,8 +213,9 @@ setup:
 ---
 "Create illegal split indices":
   - skip:
-      version: " - 6.0.99"
-      reason: Added in 6.1.0
+      version: " - 6.99.99"
+      reason: expects warnings that pre-7.0.0 will not send
+      features: "warnings"
 
   # try to do an illegal split with number_of_routing_shards set
   - do:
@@ -224,6 +230,8 @@ setup:
             index.number_of_replicas: 0
             index.number_of_shards: 4
             index.number_of_routing_shards: 8
+      warnings:
+        - "resize operations without copying settings is deprecated; set parameter [copy_settings] to [true] for future default behavior"
 
   # try to do an illegal split with illegal number_of_shards
   - do:
@@ -237,3 +245,5 @@ setup:
           settings:
             index.number_of_replicas: 0
             index.number_of_shards: 6
+      warnings:
+        - "resize operations without copying settings is deprecated; set parameter [copy_settings] to [true] for future default behavior"

rest-api-spec/src/main/resources/rest-api-spec/test/indices.split/20_source_mapping.yml

@@ -1,12 +1,12 @@
 ---
 "Split index ignores target template mapping":
-#  - skip:
-#      version: " - 6.0.99"
-#      reason: Added in 6.1.0
-# uncomment once AwaitsFix is resolved
   - skip:
+      # when re-enabling uncomment the below skips
       version: "all"
       reason: "AwaitsFix'ing, see https://github.com/elastic/elasticsearch/issues/30503"
+      # version: " - 6.99.99"
+      # reason: expects warnings that pre-7.0.0 will not send
+      features: "warnings"
 
   # create index
   - do:
@@ -68,6 +68,8 @@
           settings:
             index.number_of_shards: 2
             index.number_of_replicas: 0
+      warnings:
+        - "resize operations without copying settings is deprecated; set parameter [copy_settings] to [true] for future default behavior"
 
   - do:
       cluster.health:

rest-api-spec/src/main/resources/rest-api-spec/test/indices.split/30_copy_settings.yml

@@ -1,8 +1,8 @@
 ---
 "Copy settings during split index":
   - skip:
-      version: " - 6.3.99"
-      reason:  copy_settings did not exist prior to 6.4.0
+      version: " - 6.99.99"
+      reason: expects warnings that pre-7.0.0 will not send
       features: "warnings"
 
   - do:
@@ -50,8 +50,6 @@
             index.number_of_replicas: 0
             index.number_of_shards: 2
             index.merge.scheduler.max_thread_count: 2
-      warnings:
-        - "parameter [copy_settings] is deprecated but was [true]"
 
   - do:
       cluster.health:
@@ -67,21 +65,20 @@
   - match: { copy-settings-target.settings.index.blocks.write: "true" }
   - match: { copy-settings-target.settings.index.routing.allocation.include._id: $master }
 
-  # now we do a actual shrink and do not copy settings
+  # now we do a actual shrink and do not copy settings (by default)
   - do:
       indices.split:
         index: "source"
         target: "no-copy-settings-target"
         wait_for_active_shards: 1
         master_timeout: 10s
-        copy_settings: false
         body:
           settings:
             index.number_of_replicas: 0
             index.number_of_shards: 2
             index.merge.scheduler.max_thread_count: 2
       warnings:
-        - "parameter [copy_settings] is deprecated but was [false]"
+        - "resize operations without copying settings is deprecated; set parameter [copy_settings] to [true] for future default behavior"
 
   - do:
       cluster.health:
@@ -96,3 +93,15 @@
   - match: { no-copy-settings-target.settings.index.merge.scheduler.max_thread_count: "2" }
   - is_false: no-copy-settings-target.settings.index.blocks.write
   - is_false: no-copy-settings-target.settings.index.routing.allocation.include._id
+
+  - do:
+      catch: /illegal_argument_exception/
+      indices.split:
+        index: "source"
+        target: "explicit-no-copy-settings-target"
+        wait_for_active_shards: 1
+        master_timeout: 10s
+        copy_settings: false
+        body:
+          settings:
+            index.number_of_replicas: 0