stream huge excel file using exceljs in node

Question

I am using exceljs to stream files. Unfortunately, when file is too large it fires 502 bad gateway error after 2 minutes(I've increased it from 1 minute in nginx). As I understand, streaming large files should not fire timeout.

  const specification_abc_xyz = [
    { header: "", key: "index", width: 6 },
    { header: "1", key: "name", width: 120 },
    { header: "2", key: "share", width: 23 },
    { header: "3", key: "cum_share", width: 25 },
    { header: "4", key: "coeff", width: 29 },
    { header: "5", key: "abc", width: 10 },
    { header: "6", key: "xyz", width: 10 },
  ];

knexPromise({}).then((abc_xyz) => {
      var options = {
        stream: res, // write to server response
        useStyles: false,
        useSharedStrings: false,
      };

      let workbook = new Excel.stream.xlsx.WorkbookWriter(options);
      let worksheet = workbook.addWorksheet("Tutorials");

      res.status(200);
      res.setHeader("Content-disposition", "attachment; filename=db_dump.xls");
      res.setHeader("Content-type", "application/vnd.ms-excel");

      worksheet.columns = specification_abc_xyz;

      abc_xyz.rows.forEach((count, idx) => {
        count.index = idx + 1;
        worksheet.addRow(count).commit();
      });
      worksheet.commit();

      return workbook.commit().then(function () {
        res.status(200).end();
      });

Maybe I am using streaming wrong. Is it possible to stream large files without increasing timeout? Thanks in advance.

Answer 1

"As I understand, streaming large files should not fire timeout."
It sounds like its not. It sounds like your gateway has a timeout that when any request exceeds that amount of time it closes the connection. Streaming of the file is not throwing a timeout, its just taking too long so the gateway closes the connection. You need to either speed up the reading and writing of the file or else extend your gateway timeout.