[[breaking_50_settings_changes]] === Settings changes From Elasticsearch 5.0 on all settings are validated before they are applied. Node level and default index level settings are validated on node startup, dynamic cluster and index setting are validated before they are updated/added to the cluster state. Every setting must be a *known* setting. All settings must have been registered with the node or transport client they are used with. This implies that plugins that define custom settings must register all of their settings during plugin loading using the `SettingsModule#registerSettings(Setting)` method. ==== Index Level Settings In previous versions Elasticsearch allowed to specify index level setting as _defaults_ on the node level, inside the `elasticsearch.yaml` file or even via command-line parameters. From Elasticsearch 5.0 on only selected settings like for instance `index.codec` can be set on the node level. All other settings must be set on each individual index. To set default values on every index, index templates should be used instead. ==== Node settings The `name` setting has been removed and is replaced by `node.name`. Usage of `-Dname=some_node_name` is not supported anymore. The `node.add_id_to_custom_path` was renamed to `add_lock_id_to_custom_path`. The default for the `node.name` settings is now the first 7 charachters of the node id, which is in turn a randomly generated UUID. The settings `node.mode` and `node.local` are removed. Local mode should be configured via `discovery.type: local` and `transport.type:local`. In order to disable _http_ please use `http.enabled: false` ==== Node attribute settings Node level attributes used for allocation filtering, forced awareness or other node identification / grouping must be prefixed with `node.attr`. In previous versions it was possible to specify node attributes with the `node.` prefix. All node attributes except of `node.master`, `node.data` and `node.ingest` must be moved to the new `node.attr.` namespace. ==== Node types settings The `node.client` setting has been removed. A node with such a setting set will not start up. Instead, each node role needs to be set separately using the existing `node.master`, `node.data` and `node.ingest` supported static settings. ==== Gateway settings The `gateway.format` setting for configuring global and index state serialization format has been removed. By default, `smile` is used as the format. ==== Transport Settings All settings with a `netty` infix have been replaced by their already existing `transport` synonyms. For instance `transport.netty.bind_host` is no longer supported and should be replaced by the superseding setting `transport.bind_host`. ==== Security manager settings The option to disable the security manager `security.manager.enabled` has been removed. In order to grant special permissions to elasticsearch users must edit the local Java Security Policy. ==== Network settings The `_non_loopback_` value for settings like `network.host` would arbitrarily pick the first interface not marked as loopback. Instead, specify by address scope (e.g. `_local_,_site_` for all loopback and private network addresses) or by explicit interface names, hostnames, or addresses. The `netty.epollBugWorkaround` settings is removed. This settings allow people to enable a netty work around for https://github.com/netty/netty/issues/327[a high CPU usage issue] with early JVM versions. This bug was http://bugs.java.com/view_bug.do?bug_id=6403933[fixed in Java 7]. Since Elasticsearch 5.0 requires Java 8 the settings is removed. Note that if the workaround needs to be reintroduced you can still set the `org.jboss.netty.epollBugWorkaround` system property to control Netty directly. ==== Forbid changing of thread pool types Previously, <> could be dynamically adjusted. The thread pool type effectively controls the backing queue for the thread pool and modifying this is an expert setting with minimal practical benefits and high risk of being misused. The ability to change the thread pool type for any thread pool has been removed. It is still possible to adjust relevant thread pool parameters for each of the thread pools (e.g., depending on the thread pool type, `keep_alive`, `queue_size`, etc.). ==== Threadpool settings The `suggest` threadpool has been removed, now suggest requests use the `search` threadpool. The prefix on all thread pool settings has been changed from `threadpool` to `thread_pool`. The minimum size setting for a scaling thread pool has been changed from `min` to `core`. The maximum size setting for a scaling thread pool has been changed from `size` to `max`. The queue size setting for a fixed thread pool must be `queue_size` (all other variants that were previously supported are no longer supported). Thread pool settings are now node-level settings. As such, it is not possible to update thread pool settings via the cluster settings API. ==== Analysis settings The `index.analysis.analyzer.default_index` analyzer is not supported anymore. If you wish to change the analyzer to use for indexing, change the `index.analysis.analyzer.default` analyzer instead. ==== Ping settings Previously, there were three settings for the ping timeout: `discovery.zen.initial_ping_timeout`, `discovery.zen.ping.timeout` and `discovery.zen.ping_timeout`. The former two have been removed and the only setting key for the ping timeout is now `discovery.zen.ping_timeout`. The default value for ping timeouts remains at three seconds. `discovery.zen.master_election.filter_client` and `discovery.zen.master_election.filter_data` have been removed in favor of the new `discovery.zen.master_election.ignore_non_master_pings`. This setting control how ping responses are interpreted during master election and should be used with care and only in extreme cases. See documentation for details. ==== Recovery settings Recovery settings deprecated in 1.x have been removed: * `index.shard.recovery.translog_size` is superseded by `indices.recovery.translog_size` * `index.shard.recovery.translog_ops` is superseded by `indices.recovery.translog_ops` * `index.shard.recovery.file_chunk_size` is superseded by `indices.recovery.file_chunk_size` * `index.shard.recovery.concurrent_streams` is superseded by `indices.recovery.concurrent_streams` * `index.shard.recovery.concurrent_small_file_streams` is superseded by `indices.recovery.concurrent_small_file_streams` * `indices.recovery.max_size_per_sec` is superseded by `indices.recovery.max_bytes_per_sec` If you are using any of these settings please take the time to review their purpose. All of the settings above are considered _expert settings_ and should only be used if absolutely necessary. If you have set any of the above setting as persistent cluster settings please use the settings update API and set their superseded keys accordingly. The following settings have been removed without replacement * `indices.recovery.concurrent_small_file_streams` - recoveries are now single threaded. The number of concurrent outgoing recoveries are throttled via allocation deciders * `indices.recovery.concurrent_file_streams` - recoveries are now single threaded. The number of concurrent outgoing recoveries are throttled via allocation deciders ==== Translog settings The `index.translog.flush_threshold_ops` setting is not supported anymore. In order to control flushes based on the transaction log growth use `index.translog.flush_threshold_size` instead. Changing the translog type with `index.translog.fs.type` is not supported anymore, the `buffered` implementation is now the only available option and uses a fixed `8kb` buffer. The translog by default is fsynced after every `index`, `create`, `update`, `delete`, or `bulk` request. The ability to fsync on every operation is not necessary anymore. In fact, it can be a performance bottleneck and it's trappy since it enabled by a special value set on `index.translog.sync_interval`. Now, `index.translog.sync_interval` doesn't accept a value less than `100ms` which prevents fsyncing too often if async durability is enabled. The special value `0` is no longer supported. `index.translog.interval` has been removed. ==== Request Cache Settings The deprecated settings `index.cache.query.enable` and `indices.cache.query.size` have been removed and are replaced with `index.requests.cache.enable` and `indices.requests.cache.size` respectively. `indices.requests.cache.clean_interval` has been replaced with `indices.cache.clean_interval` and is no longer supported. ==== Field Data Cache Settings The `indices.fielddata.cache.clean_interval` setting has been replaced with `indices.cache.clean_interval`. ==== Allocation settings The `cluster.routing.allocation.concurrent_recoveries` setting has been replaced with `cluster.routing.allocation.node_concurrent_recoveries`. ==== Similarity settings The 'default' similarity has been renamed to 'classic'. ==== Indexing settings The `indices.memory.min_shard_index_buffer_size` and `indices.memory.max_shard_index_buffer_size` have been removed as Elasticsearch now allows any one shard to use amount of heap as long as the total indexing buffer heap used across all shards is below the node's `indices.memory.index_buffer_size` (defaults to 10% of the JVM heap). ==== Removed es.max-open-files Setting the system property es.max-open-files to true to get Elasticsearch to print the number of maximum open files for the Elasticsearch process has been removed. This same information can be obtained from the <> API, and a warning is logged on startup if it is set too low. ==== Removed es.netty.gathering Disabling Netty from using NIO gathering could be done via the escape hatch of setting the system property "es.netty.gathering" to "false". Time has proven enabling gathering by default is a non-issue and this non-documented setting has been removed. ==== Removed es.useLinkedTransferQueue The system property `es.useLinkedTransferQueue` could be used to control the queue implementation used in the cluster service and the handling of ping responses during discovery. This was an undocumented setting and has been removed. ==== Cache concurrency level settings removed Two cache concurrency level settings `indices.requests.cache.concurrency_level` and `indices.fielddata.cache.concurrency_level` because they no longer apply to the cache implementation used for the request cache and the field data cache. ==== Using system properties to configure Elasticsearch Elasticsearch can no longer be configured by setting system properties. Instead, use `-Ename.of.setting=value.of.setting`. ==== Removed using double-dashes to configure Elasticsearch Elasticsearch could previously be configured on the command line by setting settings via `--name.of.setting value.of.setting`. This feature has been removed. Instead, use `-Ename.of.setting=value.of.setting`. ==== Remove support for .properties config files The Elasticsearch configuration and logging configuration can no longer be stored in the Java properties file format (line-delimited key=value pairs with a `.properties` extension). ==== Discovery Settings The `discovery.zen.minimum_master_node` must be set for nodes that have `network.host`, `network.bind_host`, `network.publish_host`, `transport.host`, `transport.bind_host`, or `transport.publish_host` configuration options set. We see those nodes as in "production" mode and thus require the setting. ==== Realtime get setting The `action.get.realtime` setting has been removed. This setting was a fallback realtime setting for the get and mget APIs when realtime wasn't specified. Now if the parameter isn't specified we always default to true. === Script settings ==== Indexed script settings Due to the fact that indexed script has been replaced by stored scripts the following settings have been replaced to: * `script.indexed` has been replaced by `script.stored` * `script.engine.*.indexed.aggs` has been replaced by `script.engine.*.stored.aggs` (where `*` represents the script language, like `groovy`, `mustache`, `painless` etc.) * `script.engine.*.indexed.mapping` has been replaced by `script.engine.*.stored.mapping` (where `*` represents the script language, like `groovy`, `mustache`, `painless` etc.) * `script.engine.*.indexed.search` has been replaced by `script.engine.*.stored.search` (where `*` represents the script language, like `groovy`, `mustache`, `painless` etc.) * `script.engine.*.indexed.update` has been replaced by `script.engine.*.stored.update` (where `*` represents the script language, like `groovy`, `mustache`, `painless` etc.) * `script.engine.*.indexed.plugin` has been replaced by `script.engine.*.stored.plugin` (where `*` represents the script language, like `groovy`, `mustache`, `painless` etc.) ==== Script mode settings Previously script mode settings (e.g., "script.inline: true", "script.engine.groovy.inline.aggs: false", etc.) accepted a wide range of "truthy" or "falsy" values. This is now much stricter and supports only the `true` and `false` options. ==== Script sandbox settings removed Prior to 5.0 a third option could be specified for the `script.inline` and `script.stored` settings ("sandbox"). This has been removed, You can now only set `script.line: true` or `script.stored: true`. ==== Search settings The setting `index.query.bool.max_clause_count` has been removed. In order to set the maximum number of boolean clauses `indices.query.bool.max_clause_count` should be used instead. ==== Memory lock settings The setting `bootstrap.mlockall` has been renamed to `bootstrap.memory_lock`. ==== Snapshot settings The default setting `include_global_state` for restoring snapshots has been changed from `true` to `false`. It has not been changed for taking snapshots and still defaults to `true` in that case. ==== Time value parsing The unit 'w' representing weeks is no longer supported. Fractional time values (e.g., 0.5s) are no longer supported. For example, this means when setting timeouts "0.5s" will be rejected and should instead be input as "500ms". ==== Node max local storage nodes Previous versions of Elasticsearch defaulted to allowing multiple nodes to share the same data directory (up to 50). This can be confusing where users accidentally startup multiple nodes and end up thinking that they've lost data because the second node will start with an empty data directory. While the default of allowing multiple nodes is friendly to playing with forming a small cluster on a laptop, and end-users do sometimes run multiple nodes on the same host, this tends to be the exception. Keeping with Elasticsearch's continual movement towards safer out-of-the-box defaults, and optimizing for the norm instead of the exception, the default for `node.max_local_storage_nodes` is now one.