Re: WriteAsText bug or bad name?

Posted by Márton Balassi on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/WriteAsText-bug-or-bad-name-tp236p238.html

Dear Flavio,

Yes, the writeAsText() merthod really creates a folder which contains a file for each execution thread, so your threads do not block each other and the execution can use multiple cores on your machine. You can see similar results if you try it with env.execute() from an IDE.

There are filesystems, HDFS to mention the most prominent one which can transparently treat such folder structure as a single file and then it would behave as you expect. I hope this answers your question.

Best,

Marton

On Wed, Oct 29, 2014 at 8:31 PM, Flavio Pompermaier <[hidden email]> wrote:

Hi to all,

running the example at http://flink.incubator.apache.org/docs/0.7-incubating/local_execution.html I was thinking that the writeAsText on a local file was creating a text file on my local filesystem..instead it creates something similar to a sequence file (within a folder).
This is something misleading I think...or the API name is wrong or this is a bug (IMHO).
Btw..how can I modify the following program to write results in a single text file on my local filesystem?

public static void main(String[] args) throws Exception {
 ExecutionEnvironment env = ExecutionEnvironment.createLocalEnvironment();
 DataSet<String> data = env.readTextFile("file:///tmp/res.txt");
 data.filter(new FilterFunction<String>() {
   public boolean filter(String value) {
    return value.startsWith("http://");
   }
  }).writeAsText("file:///tmp/res.txt");
  env.execute();
}

Best,
Flavio