Testing the index existence

Elastic Stack Elasticsearch
1

I need to test if an index already exists, otherwise I create it by code.
In order to test if an index already exists I execute :
private boolean existsIndex() {
ClusterState cs =
client.admin().cluster().prepareState().setFilterIndices(INDICE).execute().actionGet().getState();
IndexMetaData imd = cs.getMetaData().index(INDICE);
return imd != null;
}
Howerver, somtimes, this test gives a wrong result (the index exists but
the test return false) because the index was not still recovered.
How can avoid this ?
Is there a way to synchronize that operation ?
Any different solution ?
Tks
Tullio

2

Have you just tried not checking and creating the index, then throwing
an error if you can't create it?

3

Yes, I know I can, however I prefer to test before than try/catch.
Tks
Tullio

Il giorno mercoledì 13 giugno 2012 15:39:04 UTC+2, Ævar Arnfjörð Bjarmason
ha scritto:

Have you just tried not checking and creating the index, then throwing
an error if you can't create it?

4

On Wed, 2012-06-13 at 06:28 -0700, tullio0106 wrote:

I need to test if an index already exists, otherwise I create it by
code.
In order to test if an index already exists I execute :
private boolean existsIndex() {
ClusterState cs =
client.admin().cluster().prepareState().setFilterIndices(INDICE).execute().actionGet().getState();
IndexMetaData imd = cs.getMetaData().index(INDICE);
return imd != null;
}
Howerver, somtimes, this test gives a wrong result (the index exists
but the test return false) because the index was not still recovered.
How can avoid this ?

Have you tried the index-exists API?

Is there a way to synchronize that operation ?
Any different solution ?
Tks
Tullio

5

Is more or less what I did with my code.
My installation is embedded and I need to use Java API, howewer what I did
is the same, but the problem is a timing problem.
When I test index is not yet recovered and return false even if the index
exists.
Tks
Tullio

Il giorno mercoledì 13 giugno 2012 16:03:38 UTC+2, Clinton Gormley ha
scritto:

On Wed, 2012-06-13 at 06:28 -0700, tullio0106 wrote:

I need to test if an index already exists, otherwise I create it by
code.
In order to test if an index already exists I execute :
private boolean existsIndex() {
ClusterState cs =

client.admin().cluster().prepareState().setFilterIndices(INDICE).execute().actionGet().getState();

    IndexMetaData imd = cs.getMetaData().index(INDICE); 
    return imd != null; 
}

Howerver, somtimes, this test gives a wrong result (the index exists
but the test return false) because the index was not still recovered.
How can avoid this ?

Have you tried the index-exists API?

Elasticsearch Platform — Find real-time answers at scale | Elastic

Is there a way to synchronize that operation ?
Any different solution ?
Tks
Tullio

6

Hi Tulio,

Have a look at his method :
https://github.com/dadoonet/spring-elasticsearch/blob/master/src/main/java/fr/pilato/spring/elasticsearch/ElasticsearchAbstractClientFactoryBean.java#L567

HTH
David

Le 13 juin 2012 à 16:07, tullio0106 tbettinazzi@axioma.it a écrit :

Is more or less what I did with my code.
My installation is embedded and I need to use Java API, howewer what I did is
the same, but the problem is a timing problem.
When I test index is not yet recovered and return false even if the index
exists.
Tks
Tullio

Il giorno mercoledì 13 giugno 2012 16:03:38 UTC+2, Clinton Gormley ha
scritto:

On Wed, 2012-06-13 at 06:28 -0700, tullio0106 wrote:
I need to test if an index already exists, otherwise I create it by
code.
In order to test if an index already exists I execute :
private boolean existsIndex() {
ClusterState cs =
client.admin().cluster().prepareState().setFilterIndices(INDICE).execute().actionGet().getState();
IndexMetaData imd = cs.getMetaData().index(INDICE);
return imd != null;
}
Howerver, somtimes, this test gives a wrong result (the index exists
but the test return false) because the index was not still recovered.
How can avoid this ?

Have you tried the index-exists API?

Elasticsearch Platform — Find real-time answers at scale | Elastic

Is there a way to synchronize that operation ?
Any different solution ?
Tks
Tullio

http://www.elasticsearch.org/guide/reference/api/admin-indices-indices-exists.html

http://www.elasticsearch.org/guide/reference/api/admin-indices-indices-exists.html

--
David Pilato
http://dev.david.pilato.fr/
Twitter : @dadoonet

7

On Wed, Jun 13, 2012 at 3:44 PM, tullio0106 tbettinazzi@axioma.it wrote:

Yes, I know I can, however I prefer to test before than try/catch.

Why?

If you have an API that can create an index but throw an exception if
one exists, why wouldn't you use it and instead opt for an API that'll
always have a race condition, Elasticsearch does not guarantee any
transactionality between API calls, so you can't call "index_exists"
and guarantee that it won't exists 10ms later when you try to create
your own index.

8

You can use the cluster health API and wait for yellow status.

On Wed, Jun 13, 2012 at 3:28 PM, tullio0106 tbettinazzi@axioma.it wrote:

I need to test if an index already exists, otherwise I create it by code.
In order to test if an index already exists I execute :
private boolean existsIndex() {
ClusterState cs =
client.admin().cluster().prepareState().setFilterIndices(INDICE).execute().actionGet().getState();
IndexMetaData imd = cs.getMetaData().index(INDICE);
return imd != null;
}
Howerver, somtimes, this test gives a wrong result (the index exists but
the test return false) because the index was not still recovered.
How can avoid this ?
Is there a way to synchronize that operation ?
Any different solution ?
Tks
Tullio

9

Hi David!
I am using your v1.3.0 of the ElasticsearchAbstractClientFactory bean and I have the same problem as explained in the beginning of the post. Since the index is not recovered by the time of trying to create the index, using a prepareExists is also returning false (does not exist) and raising an error. The solution I use is simply to catch the IndexAlreadyExistsException. I am writing this as feedback to your post in case you want to consider it for further versions of your factories.

Ibai