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Message ID: 804
Entry time: 20 Jun 2012
Reply to this: 818
lazylogger write to HADOOP HDFS
I tried using the lazylogger "Disk" method to write into a HADOOP HDFS clustered filesystem and found a
number of problems. I ended up replacing the lazylogger lazy_copy() function that still uses former YBOS
code with a new lazy_disk_copy() function that uses generic fread/fwrite. Also fixed the situation where
lazylogger cannot cleanly stop from the mhttpd "programs/stop" button while it is busy writing (the fix
works only for the "Disk" method).
(Note that one can also use the "Script" method for writing into HDFS)
Anyhow, the new lazylogger writes into HDFS just fine and I expect that it would also work for writing into
DCACHE using PNFS (if ever we get the SL6 PNFS working with our DCACHE servers).
Writing into our test HDFS cluster runs at about 20 MiBytes/sec for 1GB files with replication set to 3.
svn rev 5295