I am not wise enough in the ways of Storm to tell you how you should partition data across bolts. However, there is no need in Hive for all data for a partition to be in the same file, only in the same directory. So if each bolt creates a file for each partition and then all those files are placed in one directory and loaded into Hive it will work.
Alan. On Jan 6, 2014, at 6:26 PM, Chen Wang <[email protected]> wrote: > Alan, > the problem is that the data is partitioned by epoch ten hourly, and i want > all data belong to that partition to be written into one file named with that > partition. How can i share the file writer across different bolt? should I > instruct data within the same partition to the same bolt? > Thanks, > Chen > > > On Fri, Jan 3, 2014 at 3:27 PM, Alan Gates <[email protected]> wrote: > You shouldn’t need to write each record to a separate file. Each Storm bolt > should be able to write to it’s own file, appending records as it goes. As > long as you only have one writer per file this should be fine. You can then > close the files every 15 minutes (or whatever works for you) and have a > separate job that creates a new partition in your Hive table with the files > created by your bolts. > > Alan. > > On Jan 2, 2014, at 11:58 AM, Chen Wang <[email protected]> wrote: > >> Guys, >> I am using storm to read data stream from our socket server, entry by entry, >> and then write them to file: one entry per file. At some point, i need to >> import the data into my hive table. There are several approaches i could >> think of: >> 1. directly write to hive hdfs file whenever I get the entry(from our socket >> server). The problem is that this could be very inefficient, since we have >> huge amount of data stream, and I would not want to write to hive hdfs one >> by one. >> Or >> 2 i can write the entries to files(normal file or hdfs file) on the disk, >> and then have a separate job to merge those small files into big one, and >> then load them into hive table. >> The problem with this is, a) how can I merge small files into big files for >> hive? b) what is the best file size to upload to hive? >> >> I am seeking advice on both approaches, and appreciate your insight. >> Thanks, >> Chen >> > > > -- > CONFIDENTIALITY NOTICE > NOTICE: This message is intended for the use of the individual or entity to > which it is addressed and may contain information that is confidential, > privileged and exempt from disclosure under applicable law. If the reader > of this message is not the intended recipient, you are hereby notified that > any printing, copying, dissemination, distribution, disclosure or > forwarding of this communication is strictly prohibited. If you have > received this communication in error, please contact the sender immediately > and delete it from your system. Thank You. > -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.
