- Elasticsearch Guide: other versions:
- Getting Started
- Setup
- Breaking changes
- Breaking changes in 2.3
- Breaking changes in 2.2
- Breaking changes in 2.1
- Breaking changes in 2.0
- Removed features
- Network changes
- Multiple
path.data
striping - Mapping changes
- CRUD and routing changes
- Query DSL changes
- Search changes
- Aggregation changes
- Parent/Child changes
- Scripting changes
- Index API changes
- Snapshot and Restore changes
- Plugin and packaging changes
- Setting changes
- Stats, info, and
cat
changes - Java API changes
- API Conventions
- Document APIs
- Search APIs
- Aggregations
- Metrics Aggregations
- Avg Aggregation
- Cardinality Aggregation
- Extended Stats Aggregation
- Geo Bounds Aggregation
- Geo Centroid Aggregation
- Max Aggregation
- Min Aggregation
- Percentiles Aggregation
- Percentile Ranks Aggregation
- Scripted Metric Aggregation
- Stats Aggregation
- Sum Aggregation
- Top hits Aggregation
- Value Count Aggregation
- Bucket Aggregations
- Children Aggregation
- Date Histogram Aggregation
- Date Range Aggregation
- Filter Aggregation
- Filters Aggregation
- Geo Distance Aggregation
- GeoHash grid Aggregation
- Global Aggregation
- Histogram Aggregation
- IPv4 Range Aggregation
- Missing Aggregation
- Nested Aggregation
- Range Aggregation
- Reverse nested Aggregation
- Sampler Aggregation
- Significant Terms Aggregation
- Terms Aggregation
- Pipeline Aggregations
- Avg Bucket Aggregation
- Derivative Aggregation
- Max Bucket Aggregation
- Min Bucket Aggregation
- Sum Bucket Aggregation
- Stats Bucket Aggregation
- Extended Stats Bucket Aggregation
- Percentiles Bucket Aggregation
- Moving Average Aggregation
- Cumulative Sum Aggregation
- Bucket Script Aggregation
- Bucket Selector Aggregation
- Serial Differencing Aggregation
- Caching heavy aggregations
- Returning only aggregation results
- Aggregation Metadata
- Metrics Aggregations
- Indices APIs
- Create Index
- Delete Index
- Get Index
- Indices Exists
- Open / Close Index API
- Put Mapping
- Get Mapping
- Get Field Mapping
- Types Exists
- Index Aliases
- Update Indices Settings
- Get Settings
- Analyze
- Index Templates
- Warmers
- Shadow replica indices
- Indices Stats
- Indices Segments
- Indices Recovery
- Indices Shard Stores
- Clear Cache
- Flush
- Refresh
- Force Merge
- Optimize
- Upgrade
- cat APIs
- Cluster APIs
- Query DSL
- Mapping
- Field datatypes
- Meta-Fields
- Mapping parameters
analyzer
boost
coerce
copy_to
doc_values
dynamic
enabled
fielddata
format
geohash
geohash_precision
geohash_prefix
ignore_above
ignore_malformed
include_in_all
index
index_options
lat_lon
fields
norms
null_value
position_increment_gap
precision_step
properties
search_analyzer
similarity
store
term_vector
- Dynamic Mapping
- Transform
- Analysis
- Analyzers
- Tokenizers
- Token Filters
- Standard Token Filter
- ASCII Folding Token Filter
- Length Token Filter
- Lowercase Token Filter
- Uppercase Token Filter
- NGram Token Filter
- Edge NGram Token Filter
- Porter Stem Token Filter
- Shingle Token Filter
- Stop Token Filter
- Word Delimiter Token Filter
- Stemmer Token Filter
- Stemmer Override Token Filter
- Keyword Marker Token Filter
- Keyword Repeat Token Filter
- KStem Token Filter
- Snowball Token Filter
- Phonetic Token Filter
- Synonym Token Filter
- Compound Word Token Filter
- Reverse Token Filter
- Elision Token Filter
- Truncate Token Filter
- Unique Token Filter
- Pattern Capture Token Filter
- Pattern Replace Token Filter
- Trim Token Filter
- Limit Token Count Token Filter
- Hunspell Token Filter
- Common Grams Token Filter
- Normalization Token Filter
- CJK Width Token Filter
- CJK Bigram Token Filter
- Delimited Payload Token Filter
- Keep Words Token Filter
- Keep Types Token Filter
- Classic Token Filter
- Apostrophe Token Filter
- Decimal Digit Token Filter
- Character Filters
- Modules
- Index Modules
- Testing
- Glossary of terms
- Release Notes
- 2.3.5 Release Notes
- 2.3.4 Release Notes
- 2.3.3 Release Notes
- 2.3.2 Release Notes
- 2.3.1 Release Notes
- 2.3.0 Release Notes
- 2.2.2 Release Notes
- 2.2.1 Release Notes
- 2.2.0 Release Notes
- 2.1.2 Release Notes
- 2.1.1 Release Notes
- 2.1.0 Release Notes
- 2.0.2 Release Notes
- 2.0.1 Release Notes
- 2.0.0 Release Notes
- 2.0.0-rc1 Release Notes
- 2.0.0-beta2 Release Notes
- 2.0.0-beta1 Release Notes
WARNING: Version 2.3 of Elasticsearch has passed its EOL date.
This documentation is no longer being maintained and may be removed. If you are running this version, we strongly advise you to upgrade. For the latest information, see the current release documentation.
Indices Segments
editIndices Segments
editProvide low level segments information that a Lucene index (shard level) is built with. Allows to be used to provide more information on the state of a shard and an index, possibly optimization information, data "wasted" on deletes, and so on.
Endpoints include segments for a specific index, several indices, or all:
curl -XGET 'http://localhost:9200/test/_segments' curl -XGET 'http://localhost:9200/test1,test2/_segments' curl -XGET 'http://localhost:9200/_segments'
Response:
{ ... "_3": { "generation": 3, "num_docs": 1121, "deleted_docs": 53, "size_in_bytes": 228288, "memory_in_bytes": 3211, "committed": true, "search": true, "version": "4.6", "compound": true } ... }
- _0
- The key of the JSON document is the name of the segment. This name is used to generate file names: all files starting with this segment name in the directory of the shard belong to this segment.
- generation
- A generation number that is basically incremented when needing to write a new segment. The segment name is derived from this generation number.
- num_docs
- The number of non-deleted documents that are stored in this segment.
- deleted_docs
- The number of deleted documents that are stored in this segment. It is perfectly fine if this number is greater than 0, space is going to be reclaimed when this segment gets merged.
- size_in_bytes
- The amount of disk space that this segment uses, in bytes.
- memory_in_bytes
- Segments need to store some data into memory in order to be searchable efficiently. This number returns the number of bytes that are used for that purpose. A value of -1 indicates that Elasticsearch was not able to compute this number.
- committed
- Whether the segment has been sync’ed on disk. Segments that are committed would survive a hard reboot. No need to worry in case of false, the data from uncommitted segments is also stored in the transaction log so that Elasticsearch is able to replay changes on the next start.
- search
- Whether the segment is searchable. A value of false would most likely mean that the segment has been written to disk but no refresh occurred since then to make it searchable.
- version
- The version of Lucene that has been used to write this segment.
- compound
- Whether the segment is stored in a compound file. When true, this means that Lucene merged all files from the segment in a single one in order to save file descriptors.
Verbose mode
editTo add additional information that can be used for debugging, use the verbose
flag.
The format of the additional verbose information is experimental and can change at any time
curl -XGET 'http://localhost:9200/test/_segments?verbose=true'
Response:
{ ... "_3": { ... "ram_tree": [ { "description": "postings [PerFieldPostings(format=1)]", "size_in_bytes": 2696, "children": [ { "description": "format 'Lucene50_0' ...", "size_in_bytes": 2608, "children" :[ ... ] }, ... ] }, ... ] } ... }
On this page