Add support for waiting for other jobs by name

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index b21d27e3b15fb74325703a60de6455cef6960596..7c24c1b74296aa33cdff97eca9458defd291b6ca 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -305,6 +305,16 @@ name=str   ASCII name of the job. This may be used to override the
                special purpose of also signaling the start of a new
                job.
 
+wait_for=str   Specifies the name of the already defined job to wait
+               for. Single waitee name only may be specified. If set, the job
+               won't be started until all workers of the waitee job are done.
+
+               Wait_for operates on the job name basis, so there are a few
+               limitations. First, the waitee must be defined prior to the
+               waiter job (meaning no forward references). Second, if a job
+               is being referenced as a waitee, it must have a unique name
+               (no duplicate waitees).
+
 description=str        Text description of the job. Doesn't do anything except
                dump this text description when this job is run. It's
                not parsed.
@@ -767,20 +777,14 @@ ioengine=str      Defines how the job issues io to the file. The following
                                defines engine specific options.
 
                        libhdfs Read and write through Hadoop (HDFS).
-                               The 'filename' option is used to specify host,
-                               port of the hdfs name-node to connect. This
-                               engine interprets offsets a little
+                               This engine interprets offsets a little
                                differently. In HDFS, files once created
                                cannot be modified. So random writes are not
                                possible. To imitate this, libhdfs engine
-                               expects bunch of small files to be created
-                               over HDFS, and engine will randomly pick a
-                               file out of those files based on the offset
-                               generated by fio backend. (see the example
-                               job file to create such files, use rw=write
-                               option). Please note, you might want to set
-                               necessary environment variables to work with
-                               hdfs/libhdfs properly.
+                               creates bunch of small files, and engine will
+                               pick a file out of those files based on the 
+                               offset enerated by fio backend. Each jobs uses
+                               it's own connection to HDFS.
 
                        mtd     Read, write and erase an MTD character device
                                (e.g., /dev/mtd0). Discards are treated as
@@ -1785,11 +1789,13 @@ that defines them is selected.
                If the job is a TCP listener or UDP reader, the hostname is not
                used and must be omitted unless it is a valid UDP multicast
                address.
+[libhdfs] namenode=str The host name or IP address of a HDFS cluster namenode to contact.
 
 [netsplice] port=int
 [net] port=int The TCP or UDP port to bind to or connect to. If this is used
 with numjobs to spawn multiple instances of the same job type, then this will
 be the starting port number since fio will use a range of ports.
+[libhdfs] port=int     the listening port of the HFDS cluster namenode.
 
 [netsplice] interface=str
 [net] interface=str  The IP address of the network interface used to send or
@@ -1848,6 +1854,9 @@ be the starting port number since fio will use a range of ports.
 
 [mtd] skip_bad=bool    Skip operations against known bad blocks.
 
+[libhdfs] hdfsdirectory        libhdfs will create chunk in this HDFS directory
+[libhdfs] chunck_size  the size of the chunck to use for each file.
+
 
 6.0 Interpreting the output
 ---------------------------