Tablestore:Query time series data

Prerequisites

A client is initialized. For more information, see Initialize a Tablestore client.

Method

public GetTimeseriesDataResponse getTimeseriesData(GetTimeseriesDataRequest request) throws TableStoreException, ClientException

Sample code

The following sample code provides an example on how to query time series data that meets specific conditions in a time series table named timeseries_table_sample:

private static void getTimeseriesData(TimeseriesClient client) {
    String tableName = "timeseries_table_sample";
    GetTimeseriesDataRequest getTimeseriesDataRequest = new GetTimeseriesDataRequest(tableName);
    
    // Specify the time series identifiers. In this example, the metric name is cpu, the data source is host_0, and the tags are "region=hangzhou" and "os=Ubuntu16.04".
    Map<String, String> tags = new HashMap<String, String>();
    tags.put("region", "hangzhou");
    tags.put("os", "Ubuntu16.04");
    TimeseriesKey timeseriesKey = new TimeseriesKey("cpu", "host_0", tags);
    getTimeseriesDataRequest.setTimeseriesKey(timeseriesKey);
    
    // Specify the time range.
    getTimeseriesDataRequest.setTimeRange(0, (System.currentTimeMillis() + 60 * 1000) * 1000);
    getTimeseriesDataRequest.setLimit(20);
    
    // Query time series data.
    GetTimeseriesDataResponse getTimeseriesDataResponse = client.getTimeseriesData(getTimeseriesDataRequest);
    // Print the query results.
    getTimeseriesDataResponse.getRows().forEach(row -> {
        System.out.println("TimeseriesKey: " + row.getTimeseriesKey() + "; TimeInUs: " + row.getTimeInUs() + "; Fields: " + row.getFields());
    });
}

When you query time series data, you can also refer to the following sample code to configure specific settings:

• Specify the maximum number of rows to return in a single request

  getTimeseriesDataRequest.setLimit(20);

• Specify that data is read in reverse chronological order

  // Read data in reverse chronological order to obtain the latest data of a time series.
  getTimeseriesDataRequest.setBackward(true);

• Specify the data columns that you want to return

   getTimeseriesDataRequest.addFieldToGet("col_string", ColumnType.STRING);
   getTimeseriesDataRequest.addFieldToGet("col_long", ColumnType.INTEGER);
   getTimeseriesDataRequest.addFieldToGet("col_double", ColumnType.DOUBLE);

• Perform paged query by using the nextToken parameter

  // If the value of the nextToken parameter is not empty, you can initiate the next request.
  if (getTimeseriesDataResponse.getNextToken() != null) {
      // Obtain the value of the nextToken parameter.
      byte[] nextToken = getTimeseriesDataResponse.getNextToken();
      
      /*
      // If you want to persist the nextToken parameter or transfer the nextToken parameter to the frontend page, you can use Base64 to encode the nextToken parameter into a string for storage and transmission.
      String tokenAsString = Base64.toBase64String(nextToken);
      // Decode the string back to byte[] type nextToken.
      byte[] tokenAsByte = Base64.fromBase64String(tokenAsString);
      */
      
      // Specify the value of the nextToken parameter.
      getTimeseriesDataRequest.setNextToken(nextToken);
      // Query time series data.
      getTimeseriesDataResponse = client.getTimeseriesData(getTimeseriesDataRequest);
      // Print the query results.
      getTimeseriesDataResponse.getRows().forEach(row -> {
          System.out.println("TimeseriesKey: " + row.getTimeseriesKey() + "; TimeInUs: " + row.getTimeInUs() + "; Fields: " + row.getFields());
      });
  }

FAQ

• Can I immediately query the data that I just wrote to a time series table?

• How do I delete time series data?