Exception when using source filtering on a large integer field

[ohadravid]

Elasticsearch version (bin/elasticsearch --version): 6.3.1 using the official docker image

Plugins installed: []

Description of the problem including expected versus actual behavior:

When indexing a document with a large integer field as (with keyword mappings`, querying fails with an error when using source filtering.
This seems a bit similar to #31853, but different enough that I thought I should open an issue.

Steps to reproduce:

1. Using the official Elasticsearch package in python:

es.indices.create('test-index')
es.indices.put_mapping(doc_type='doc', index='test-index', body={
    'properties': {
        'offset': {
            'type': 'keyword'
        }
    }
})
es.index('test-index', 'doc', {'offset': 2 ** 2500})

2. While a regular query works as expected:

>>> es.search(index='test-index', body={
    'query': {'match_all': {}}, 
    'size': 10
})

{ 'hits': { 'hits': [ '_source': {'offset': 37....} ...}

Using source-filtering will result in an exception:

>>> es.search(index='test-index', body={
    '_source': ['offset'], 
    'query': {'match_all': {}}, 
    'size': 10
})

{'_shards': {'failed': 1,
  'failures': [{'index': 'test-index',
    'node': 'G2YpLXsGTNGrEphsO5SASQ',
    'reason': {'reason': 'cannot write xcontent for unknown value of type class java.math.BigInteger',
     'type': 'illegal_argument_exception'},
    'shard': 1}],
  'skipped': 0,
  'successful': 4,
  'total': 5},
 'hits': {'hits': [], 'max_score': 1.0, 'total': 1},
 'timed_out': False,
 'took': 8}

(Using '_source': ['*'] will result in the same error)

Provide logs (if relevant):
When using a scroll query, the server log shows the following error:

[2018-07-26T07:05:35,682][DEBUG][o.e.a.s.TransportSearchScrollAction] [server-name] [157387] Failed to execute fetch phase
org.elasticsearch.transport.RemoteTransportException: [server-name][10.0.0.7:9300][indices:data/read/search[phase/fetch/id/scroll]]
Caused by: java.lang.IllegalArgumentException: cannot write xcontent for unknown value of type class java.math.BigInteger
       at org.elasticsearch.common.xcontent.XContentBuilder.unknownValue(XContentBuilder.java:755) ~[elasticsearch-x-content-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.xcontent.XContentBuilder.map(XContentBuilder.java:810) ~[elasticsearch-x-content-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.xcontent.XContentBuilder.unknownValue(XContentBuilder.java:744) ~[elasticsearch-x-content-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.xcontent.XContentBuilder.value(XContentBuilder.java:837) ~[elasticsearch-x-content-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.xcontent.XContentBuilder.unknownValue(XContentBuilder.java:746) ~[elasticsearch-x-content-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.xcontent.XContentBuilder.map(XContentBuilder.java:810) ~[elasticsearch-x-content-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.xcontent.XContentBuilder.unknownValue(XContentBuilder.java:744) ~[elasticsearch-x-content-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.xcontent.XContentBuilder.value(XContentBuilder.java:726) ~[elasticsearch-x-content-6.3.1.jar:6.3.1]
       at org.elasticsearch.search.fetch.subphase.FetchSourceSubPhase.hitExecute(FetchSourceSubPhase.java:65) ~[elasticsearch-6.3.1.jar:6.3.1]
       at org.elasticsearch.search.fetch.FetchPhase.execute(FetchPhase.java:162) ~[elasticsearch-6.3.1.jar:6.3.1]
       at org.elasticsearch.search.SearchService.executeFetchPhase(SearchService.java:516) ~[elasticsearch-6.3.1.jar:6.3.1]
       at org.elasticsearch.action.search.SearchTransportService$10.messageReceived(SearchTransportService.java:430) ~[elasticsearch-6.3.1.jar:6.3.1]
       at org.elasticsearch.action.search.SearchTransportService$10.messageReceived(SearchTransportService.java:427) ~[elasticsearch-6.3.1.jar:6.3.1]
       at org.elasticsearch.transport.RequestHandlerRegistry.processMessageReceived(RequestHandlerRegistry.java:66) ~[elasticsearch-6.3.1.jar:6.3.1]
       at org.elasticsearch.transport.TransportService$7.doRun(TransportService.java:664) [elasticsearch-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.util.concurrent.ThreadContext$ContextPreservingAbstractRunnable.doRun(ThreadContext.java:725) [elasticsearch-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37) [elasticsearch-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.util.concurrent.TimedRunnable.doRun(TimedRunnable.java:41) [elasticsearch-6.3.1.jar:6.3.1]
       at org.elasticsearch.common.util.concurrent.AbstractRunnable.run(AbstractRunnable.java:37) [elasticsearch-6.3.1.jar:6.3.1]
       at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1135) [?:?]
       at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) [?:?]
       at java.lang.Thread.run(Thread.java:844) [?:?]

[elasticmachine]

Pinging @elastic/es-search-aggs

[mirkoscotti]

I have a very similar issue, starting from this trivial Java code:

<project
	xmlns="http://maven.apache.org/POM/4.0.0"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>xcontent-test</groupId>
	<artifactId>xcontent-test</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<dependencies>
		<dependency>
			<groupId>org.elasticsearch</groupId>
			<artifactId>elasticsearch</artifactId>
			<version>6.3.2</version>
		</dependency>
		<dependency>
			<groupId>org.elasticsearch.client</groupId>
			<artifactId>elasticsearch-rest-high-level-client</artifactId>
			<version>6.3.2</version>
		</dependency>
	</dependencies>
</project>

--------

package xcontent.test;

import java.math.BigDecimal;
import org.elasticsearch.index.query.QueryBuilders;

public class XContentTest
{

	public static void main(String[] args)
	{
		QueryBuilders.termQuery("myField", BigDecimal.TEN).toString();
	}
}

------------

Exception in thread "main" java.lang.IllegalArgumentException: cannot write xcontent for unknown value of type class java.math.BigDecimal
	at org.elasticsearch.common.xcontent.XContentBuilder.unknownValue(XContentBuilder.java:755)
	at org.elasticsearch.common.xcontent.XContentBuilder.value(XContentBuilder.java:726)
	at org.elasticsearch.common.xcontent.XContentBuilder.field(XContentBuilder.java:711)
	at org.elasticsearch.index.query.BaseTermQueryBuilder.doXContent(BaseTermQueryBuilder.java:154)
	at org.elasticsearch.index.query.AbstractQueryBuilder.toXContent(AbstractQueryBuilder.java:82)
	at org.elasticsearch.common.Strings.toString(Strings.java:778)
	at org.elasticsearch.index.query.AbstractQueryBuilder.toString(AbstractQueryBuilder.java:367)
	at xcontent.test.XContentTest.main(XContentTest.java:12)

Private method XContentBuilder.unknownValue in version 6.2.4 applies toString() to all values of type outside the static writers map. Why does it has been replaced by an exception thrown? I bypassed the issue with the following line, but it seems to me quite stupid:

QueryBuilders.termQuery("myField", BigDecimal.TEN.doubleValue()).toString();

What it is expected to be the right approach?

[mayya-sharipova]

Thanks for reporting this issue.
Throwing IllegalArgumentException for unknown values was done in the effort to make json encoding stricter.

I wonder if we should add to XContentBuilder json encoding of BigDecimal and BigInteger;
I will leave this point for the team discussion.