let sendChunk = () => {
        const thread = spawn(async function(input, done) {
          try {
            const path = require('path');
            const _ = require('lodash');
            const ReportLoader = require(path.resolve('./app/controllers/report-loader'));
            const Reports = new ReportLoader();
            const ImpalaQueryRunner = require(path.resolve('./app/controllers/impala-query-runner.js'));

            const reportMetadata = Reports.getReportMetadata(input.report);
            const queryRunner = new ImpalaQueryRunner(reportMetadata, input.loader.params);
            const modifiedParams = _.merge({}, input.loader.params, {startDate: input.loader.params.cacheStartDate || input.loader.params.startDate});
            const result = (input.loader.reportInfo.reportMode === 'RAW')
              ? input.chunk
              : await queryRunner.preRenderData(modifiedParams, input.chunk);

            done(result);
          } catch (e) {
            console.error(e);
          }
        });

        const chunk = {
          rows: _.map(buf, MemSqlClient.processRow),
          columns: tableCols,
        };

        return new Promise((resolve, reject) => {
          console.time('thread');
          thread
            .send({chunk, loader, report: req.query.report})
            .on('message', (response) => {
              // TODO: find out why response comes twice
              if (_.isEmpty(response)) return;

              console.timeEnd('thread');
              console.log('responded', response);
              ws.send(JSON.stringify({type: 'data', content: response}), (err) => {
                console.log('------------- socket send');
                thread.kill();
                resolve();
              });
            })
            .on('error', (error) => {
              console.error('Worker errored:', error);
              reject(error);
            })
            .on('exit', () => {
              console.log('Worker has been terminated.');
            });
        });
      };