Get Rollup Index Capabilities APIedit

This functionality is in technical preview and may be changed or removed in a future release. Elastic will work to fix any issues, but features in technical preview are not subject to the support SLA of official GA features.

The Get Rollup Index Capabilities API allows the user to determine if a concrete index or index pattern contains stored rollup jobs and data. If it contains data stored from rollup jobs, the capabilities of those jobs are returned. The API accepts a GetRollupIndexCapsRequest object as a request and returns a GetRollupIndexCapsResponse.

Get Rollup Index Capabilities Requestedit

A GetRollupIndexCapsRequest requires a single parameter: the target index or index pattern (e.g. rollup-foo):

GetRollupIndexCapsRequest getRollupIndexCapsRequest = new GetRollupIndexCapsRequest("rollup");

Executionedit

The Get Rollup Index Capabilities API can be executed through a RollupClient instance. Such instance can be retrieved from a RestHighLevelClient using the rollup() method:

GetRollupIndexCapsResponse capsResponse = client.rollup()
    .getRollupIndexCapabilities(getRollupIndexCapsRequest, RequestOptions.DEFAULT);

Responseedit

The returned GetRollupIndexCapsResponse holds lists and maps of values which correspond to the capabilities of the rollup index/index pattern (what jobs are stored in the index, their capabilities, what aggregations are available, etc). Because multiple jobs can be stored in one index, the response may include several jobs with different configurations.

The capabilities are essentially the same as the original job configuration, just presented in a different manner. For example, if we had created a job with the following config:

final String indexPattern = "docs";
final String rollupIndexName = "rollup";
final String cron = "*/1 * * * * ?";
final int pageSize = 100;
final TimeValue timeout = null;

String id = "job_1";
RollupJobConfig config = new RollupJobConfig(id, indexPattern, rollupIndexName, cron,
    pageSize, groups, metrics, timeout);

PutRollupJobRequest request = new PutRollupJobRequest(config);
AcknowledgedResponse response = client.rollup().putRollupJob(request, RequestOptions.DEFAULT);

boolean acknowledged = response.isAcknowledged();

The GetRollupIndexCapsResponse object would contain the same information, laid out in a slightly different manner:

Map<String, RollableIndexCaps> rolledPatterns = capsResponse.getJobs();

RollableIndexCaps docsPattern = rolledPatterns.get("rollup");

// indexName will be "rollup", the target index we requested
String indexName = docsPattern.getIndexName();

// Each index pattern can have multiple jobs that rolled it up, so getJobCaps()
// returns a list of jobs that rolled up the pattern
List<RollupJobCaps> rollupJobs = docsPattern.getJobCaps();
RollupJobCaps jobCaps = rollupJobs.get(0);

// jobID is the identifier we used when we created the job (e.g. job1)
String jobID = jobCaps.getJobID();

// rollupIndex is the location that the job stored it's rollup docs (e.g. rollup)
String rollupIndex = jobCaps.getRollupIndex();

// Finally, fieldCaps are the capabilities of individual fields in the config
// The key is the field name, and the value is a RollupFieldCaps object which
// provides more info.
Map<String, RollupJobCaps.RollupFieldCaps> fieldCaps = jobCaps.getFieldCaps();

// If we retrieve the "timestamp" field, it returns a list of maps.  Each list
// item represents a different aggregation that can be run against the "timestamp"
// field, and any additional details specific to that agg (interval, etc)
List<Map<String, Object>> timestampCaps = fieldCaps.get("timestamp").getAggs();
logger.error(timestampCaps.get(0).toString());
assert timestampCaps.get(0).toString().equals("{agg=date_histogram, fixed_interval=1h, delay=7d, time_zone=UTC}");

// In contrast to the timestamp field, the temperature field has multiple aggs configured
List<Map<String, Object>> temperatureCaps = fieldCaps.get("temperature").getAggs();
assert temperatureCaps.toString().equals("[{agg=min}, {agg=max}, {agg=sum}]");

Asynchronous Executionedit

This request can be executed asynchronously:

client.rollup().getRollupIndexCapabilitiesAsync(getRollupIndexCapsRequest, RequestOptions.DEFAULT, listener); 

The GetRollupIndexCapsRequest to execute and the ActionListener to use when the execution completes

The asynchronous method does not block and returns immediately. Once it is completed the ActionListener is called back using the onResponse method if the execution successfully completed or using the onFailure method if it failed.

A typical listener for GetRollupIndexCapsResponse looks like:

ActionListener<GetRollupIndexCapsResponse> listener = new ActionListener<GetRollupIndexCapsResponse>() {
    @Override
    public void onResponse(GetRollupIndexCapsResponse response) {

        
    }

    @Override
    public void onFailure(Exception e) {
        
    }
};

Called when the execution is successfully completed. The response is provided as an argument

Called in case of failure. The raised exception is provided as an argument