Remove 'term_index_interval' and 'term_index_divisor'

These settings are no longer relevant since they are codec /
postingsformat level settings since Lucene 4.0

Closes #3912

docs/reference/index-modules.asciidoc

@@ -36,24 +36,6 @@ otherwise it is written in non-compound format.  added[0.90.2]
     in compound format or non-compound format? Defaults to `true`.
     added[0.90.4]. This is a dynamic setting. added[0.90.6,Previously not dynamic]
 
-`index.term_index_interval`::
-
-	Set the interval between indexed terms.
-	Large values cause less memory to be used by a reader / searcher, but
-	slow random-access to terms. Small values cause more memory to be used
-	by a reader / searcher, and speed random-access to terms. Defaults to
-	`128`.
-
-`index.term_index_divisor`::
-	Subsamples which indexed terms are loaded
-	into RAM. This has the same effect as `index.term_index_interval` except
-	that setting must be done at indexing time while this setting can be set
-	per reader / searcher. When set to N, then one in every
-	N*termIndexInterval terms in the index is loaded into memory. By setting
-	this to a value > 1 you can reduce memory usage, at the expense of
-	higher latency when loading a TermInfo. The default value is 1. Set this
-	to -1 to skip loading the terms index entirely.
-
 `index.refresh_interval`::
 	A time setting controlling how often the
 	refresh operation will be executed. Defaults to `1s`. Can be set to `-1`

docs/reference/indices/update-settings.asciidoc

@@ -53,12 +53,6 @@ settings API:
 `index.refresh_interval`::
     The async refresh interval of a shard.
 
-`index.term_index_interval`::
-    The Lucene index term interval. Only applies to newly created docs.
-
-`index.term_index_divisor`::
-    The Lucene reader term index divisor.
-
 `index.index_concurrency`::
     Defaults to `8`.
 

src/main/java/org/elasticsearch/index/engine/robin/RobinEngine.java

@@ -89,8 +89,6 @@
 public class RobinEngine extends AbstractIndexShardComponent implements Engine {
 
     private volatile ByteSizeValue indexingBufferSize;
-    private volatile int termIndexInterval;
-    private volatile int termIndexDivisor;
     private volatile int indexConcurrency;
     private volatile boolean compoundOnFlush = true;
 
@@ -170,8 +168,6 @@ public RobinEngine(ShardId shardId, @IndexSettings Settings indexSettings, Threa
 
         this.gcDeletesInMillis = indexSettings.getAsTime(INDEX_GC_DELETES, TimeValue.timeValueSeconds(60)).millis();
         this.indexingBufferSize = componentSettings.getAsBytesSize("index_buffer_size", new ByteSizeValue(64, ByteSizeUnit.MB)); // not really important, as it is set by the IndexingMemory manager
-        this.termIndexInterval = indexSettings.getAsInt(INDEX_TERM_INDEX_INTERVAL, IndexWriterConfig.DEFAULT_TERM_INDEX_INTERVAL);
-        this.termIndexDivisor = indexSettings.getAsInt(INDEX_TERM_INDEX_DIVISOR, 1); // IndexReader#DEFAULT_TERMS_INDEX_DIVISOR
         this.codecName = indexSettings.get(INDEX_CODEC, "default");
 
         this.threadPool = threadPool;
@@ -1410,8 +1406,6 @@ private IndexWriter createWriter() throws IOException {
             config.setMergePolicy(mergePolicyProvider.newMergePolicy());
             config.setSimilarity(similarityService.similarity());
             config.setRAMBufferSizeMB(indexingBufferSize.mbFrac());
-            config.setTermIndexInterval(termIndexInterval);
-            config.setReaderTermsIndexDivisor(termIndexDivisor);
             config.setMaxThreadStates(indexConcurrency);
             config.setCodec(codecService.codec(codecName));
             /* We set this timeout to a highish value to work around
@@ -1451,8 +1445,6 @@ public void warm(AtomicReader reader) throws IOException {
         }
     }
 
-    public static final String INDEX_TERM_INDEX_INTERVAL = "index.term_index_interval";
-    public static final String INDEX_TERM_INDEX_DIVISOR = "index.term_index_divisor";
     public static final String INDEX_INDEX_CONCURRENCY = "index.index_concurrency";
     public static final String INDEX_COMPOUND_ON_FLUSH = "index.compound_on_flush";
     public static final String INDEX_GC_DELETES = "index.gc_deletes";
@@ -1475,27 +1467,13 @@ public void onRefreshSettings(Settings settings) {
                 indexWriter.getConfig().setUseCompoundFile(compoundOnFlush);
             }
 
-            int termIndexInterval = settings.getAsInt(INDEX_TERM_INDEX_INTERVAL, RobinEngine.this.termIndexInterval);
-            int termIndexDivisor = settings.getAsInt(INDEX_TERM_INDEX_DIVISOR, RobinEngine.this.termIndexDivisor); // IndexReader#DEFAULT_TERMS_INDEX_DIVISOR
             int indexConcurrency = settings.getAsInt(INDEX_INDEX_CONCURRENCY, RobinEngine.this.indexConcurrency);
             boolean failOnMergeFailure = settings.getAsBoolean(INDEX_FAIL_ON_MERGE_FAILURE, RobinEngine.this.failOnMergeFailure);
             String codecName = settings.get(INDEX_CODEC, RobinEngine.this.codecName);
             boolean requiresFlushing = false;
-            if (termIndexInterval != RobinEngine.this.termIndexInterval || termIndexDivisor != RobinEngine.this.termIndexDivisor || indexConcurrency != RobinEngine.this.indexConcurrency || !codecName.equals(RobinEngine.this.codecName) || failOnMergeFailure != RobinEngine.this.failOnMergeFailure) {
+            if (indexConcurrency != RobinEngine.this.indexConcurrency || !codecName.equals(RobinEngine.this.codecName) || failOnMergeFailure != RobinEngine.this.failOnMergeFailure) {
                 rwl.readLock().lock();
                 try {
-                    if (termIndexInterval != RobinEngine.this.termIndexInterval) {
-                        logger.info("updating index.term_index_interval from [{}] to [{}]", RobinEngine.this.termIndexInterval, termIndexInterval);
-                        RobinEngine.this.termIndexInterval = termIndexInterval;
-                        indexWriter.getConfig().setTermIndexInterval(termIndexInterval);
-                    }
-                    if (termIndexDivisor != RobinEngine.this.termIndexDivisor) {
-                        logger.info("updating index.term_index_divisor from [{}] to [{}]", RobinEngine.this.termIndexDivisor, termIndexDivisor);
-                        RobinEngine.this.termIndexDivisor = termIndexDivisor;
-                        indexWriter.getConfig().setReaderTermsIndexDivisor(termIndexDivisor);
-                        // we want to apply this right now for readers, even "current" ones
-                        requiresFlushing = true;
-                    }
                     if (indexConcurrency != RobinEngine.this.indexConcurrency) {
                         logger.info("updating index.index_concurrency from [{}] to [{}]", RobinEngine.this.indexConcurrency, indexConcurrency);
                         RobinEngine.this.indexConcurrency = indexConcurrency;

src/main/java/org/elasticsearch/index/settings/IndexDynamicSettingsModule.java

@@ -77,8 +77,6 @@ public IndexDynamicSettingsModule() {
         indexDynamicSettings.addDynamicSetting(LogDocMergePolicyProvider.INDEX_MERGE_POLICY_MAX_MERGE_DOCS, Validator.POSITIVE_INTEGER);
         indexDynamicSettings.addDynamicSetting(LogDocMergePolicyProvider.INDEX_MERGE_POLICY_MERGE_FACTOR, Validator.INTEGER_GTE_2);
         indexDynamicSettings.addDynamicSetting(LogDocMergePolicyProvider.INDEX_COMPOUND_FORMAT);
-        indexDynamicSettings.addDynamicSetting(RobinEngine.INDEX_TERM_INDEX_INTERVAL, Validator.POSITIVE_INTEGER);
-        indexDynamicSettings.addDynamicSetting(RobinEngine.INDEX_TERM_INDEX_DIVISOR, Validator.POSITIVE_INTEGER);
         indexDynamicSettings.addDynamicSetting(RobinEngine.INDEX_INDEX_CONCURRENCY, Validator.NON_NEGATIVE_INTEGER);
         indexDynamicSettings.addDynamicSetting(RobinEngine.INDEX_COMPOUND_ON_FLUSH, Validator.BOOLEAN);
         indexDynamicSettings.addDynamicSetting(RobinEngine.INDEX_GC_DELETES, Validator.TIME);