# Adding Synonyms on existing Index **URL:** \ **Category:** Elasticsearch\ **Created:** [December 2, 2011, 2:31am UTC](https://discuss.elastic.co/t/adding-synonyms-on-existing-index/6046 "2011-12-02T02:31:43Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Greg\_Brown](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/greg_brown/32/1373_2.png) [@Greg\_Brown](https://discuss.elastic.co/u/Greg_Brown)\ **Post date:** [December 2, 2011, 2:31am UTC](https://discuss.elastic.co/t/adding-synonyms-on-existing-index/6046/1 "2011-12-02T02:31:43Z")
Greetings, I have had a cluster running 0.17.8 which I just just updated to 0.18.5 and (foolishly) at the same time I added a synonym file with the mapping of "plug-in, plug in, plugin, plug-ins, plug ins, plugins". Worked fine on my test server, but when I updated the production server (so old 0.17.8 index now running 0.18.5 + synonyms) my searches for plugin stopped returning any results even though there had been results for each of the terms before. My synonym filter is using the default configuration which I think means expand == true and so any of the above terms should be rewritten to all of the terms. By reindexing I'm able to fix the problem (not surprisingly). But it would be nice to be able to apply synonyms without reindexing. Especially if/when the index gets so big that it would take weeks to completely reindex. Any suggestions on what I might have done wrong or ways to avoid reindexing in the future? My Analyzer configuration is: index : analysis : filter : light\_stemmer : type : stemmer name : minimal\_english snowball : type : snowball language : English wd\_filter : type : word\_delimiter generate\_word\_parts : true generate\_number\_parts : true catenate\_words : true split\_on\_case\_change : true preserve\_original : true split\_on\_numerics: true ac\_synonym : type : synonym synonyms\_path : ac-synonyms.txt analyzer : default : type : custom tokenizer : uax\_url\_email filter : [wd\_filter,lowercase,light\_stemmer,ac\_synonym] char\_filter : [html\_strip] Thanks -Greg ---
**Author:** ![ppearcy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ppearcy/32/980_2.png) [@ppearcy](https://discuss.elastic.co/u/ppearcy)\ **Post date:** [December 2, 2011, 6:09am UTC](https://discuss.elastic.co/t/adding-synonyms-on-existing-index/6046/2 "2011-12-02T06:09:37Z")
You could apply the synonym filter to the search analyzer only. Otherwise, I'm pretty sure you need to re-index. On Dec 1, 7:31 pm, Greg Brown [gbrown5...@gmail.com](mailto:gbrown5...@gmail.com) wrote: > Greetings, > > I have had a cluster running 0.17.8 which I just just updated to > 0.18.5 and (foolishly) at the same time I added a synonym file with > the mapping of "plug-in, plug in, plugin, plug-ins, plug ins, > plugins". > > Worked fine on my test server, but when I updated the production > server (so old 0.17.8 index now running 0.18.5 + synonyms) my searches > for plugin stopped returning any results even though there had been > results for each of the terms before. My synonym filter is using the > default configuration which I think means expand == true and so any of > the above terms should be rewritten to all of the terms. > > By reindexing I'm able to fix the problem (not surprisingly). But it > would be nice to be able to apply synonyms without reindexing. > Especially if/when the index gets so big that it would take weeks to > completely reindex. Any suggestions on what I might have done wrong or > ways to avoid reindexing in the future? > > My Analyzer configuration is: > index : > analysis : > filter : > light\_stemmer : > type : stemmer > name : minimal\_english > snowball : > type : snowball > language : English > wd\_filter : > type : word\_delimiter > generate\_word\_parts : true > generate\_number\_parts : true > catenate\_words : true > split\_on\_case\_change : true > preserve\_original : true > split\_on\_numerics: true > ac\_synonym : > type : synonym > synonyms\_path : ac-synonyms.txt > analyzer : > default : > type : custom > tokenizer : uax\_url\_email > filter : [wd\_filter,lowercase,light\_stemmer,ac\_synonym] > char\_filter : [html\_strip] > > Thanks > -Greg ---
**Author:** ![kimchy](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/kimchy/32/44952_2.png) [@kimchy](https://discuss.elastic.co/u/kimchy)\ **Post date:** [December 2, 2011, 2:48pm UTC](https://discuss.elastic.co/t/adding-synonyms-on-existing-index/6046/3 "2011-12-02T14:48:07Z")
You can update the synonym file itself, and then close and open the index, it will re-read the synonym file. On Fri, Dec 2, 2011 at 4:31 AM, Greg Brown [gbrown5878@gmail.com](mailto:gbrown5878@gmail.com) wrote: > Greetings, > > I have had a cluster running 0.17.8 which I just just updated to > 0.18.5 and (foolishly) at the same time I added a synonym file with > the mapping of "plug-in, plug in, plugin, plug-ins, plug ins, > plugins". > > Worked fine on my test server, but when I updated the production > server (so old 0.17.8 index now running 0.18.5 + synonyms) my searches > for plugin stopped returning any results even though there had been > results for each of the terms before. My synonym filter is using the > default configuration which I think means expand == true and so any of > the above terms should be rewritten to all of the terms. > > By reindexing I'm able to fix the problem (not surprisingly). But it > would be nice to be able to apply synonyms without reindexing. > Especially if/when the index gets so big that it would take weeks to > completely reindex. Any suggestions on what I might have done wrong or > ways to avoid reindexing in the future? > > My Analyzer configuration is: > index : > analysis : > filter : > light\_stemmer : > type : stemmer > name : minimal\_english > snowball : > type : snowball > language : English > wd\_filter : > type : word\_delimiter > generate\_word\_parts : true > generate\_number\_parts : true > catenate\_words : true > split\_on\_case\_change : true > preserve\_original : true > split\_on\_numerics: true > ac\_synonym : > type : synonym > synonyms\_path : ac-synonyms.txt > analyzer : > default : > type : custom > tokenizer : uax\_url\_email > filter : [wd\_filter,lowercase,light\_stemmer,ac\_synonym] > char\_filter : [html\_strip] > > Thanks > -Greg ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 3:46am UTC](https://discuss.elastic.co/t/adding-synonyms-on-existing-index/6046/4 "2017-07-06T03:46:35Z")