Parameter types

As described in the preceding table, The variable values are based on the values of system parameters. You can use custom variables to flexibly define the obtained part and format.

Example of system parameters

Set a MaxCompute SQL node to be run once every hour from 00:00 to 23:59 every day. To use system parameters in the code, follow these steps:

1. Directly reference system parameters in the code. The node code is as follows:
   insert overwrite table tb1 partition(ds ='20150304') select
   c1,c2,c3
   from (
   select * from tb2
   where ds ='${bdp.system.cyctime}') t
   full outer join(
   select * from tb3
   where ds = '${bdp.system.bizdate}') y
   on t.c1 = y.c1;

2. After the preceding step, your node is partitioned by using the system parameters. Set the scheduling time attributes and scheduling dependencies. In this example, Recurrence is set to Hour.
3. After setting the scheduling cycle and dependency, submit the node. You can check the node in O&M. The node generates periodic instances during running from the second day. You can right-click an instance and select View Log to view the time when the system parameters are parsed.

   For example, the scheduling system creates 24 running instances for the node on January 14, 2019. Because the business date is January 13, 2019 (the day before the running date) for all instances, ${bdp.system.bizdate} is always displayed as 20190113. The runtime is the running date plus the scheduled time. Therefore, ${bdp.system.cyctime} is displayed as 20190114000000 plus the scheduled time of each instance.

   Open the run logs of each instance and search for the replaced values of parameters in the code:

   • Because the scheduled time for the first instance is 2019-01-14 00:00:00, bdp.system.bizdate is replaced with 20190113, and bdp.system.cyctime is replaced with 20190114000000.
   • Because the scheduled time for the second instance is 2019-01-14 01:00:00, bdp.system.bizdate is replaced with 20190113, and bdp.system.cyctime is replaced with 20190114010000.
   • Similarly, because the scheduled time for the twenty-fourth instance is 2019-01-14 23:00:00, bdp.system.bizdate is replaced with 20190113, and bdp.system.cyctime is replaced with 20190114230000.

Custom parameters for non-SHELL nodes

1. You can enter thishour=$[yyyy-mm-dd/hh24:mi:ss] lasthour=$[yyyy-mm-dd/hh24:mi:ss-1/24] in the Parameter text box.
2. Set the node to be run once every hour.
3. After setting the scheduling cycle and dependency, submit the node. You can check the node in O&M. The node generates periodic instances during running from the second day. You can right-click an instance and select View Log to view the time when the custom parameters are parsed. Because the value of cyctime is 20190114010000, the value of thishour is 2019-01-14/01:00:00, and the value of lasthour, which represents the last hour, is 2019-01-14/00:00:00.

Custom parameters for SHELL nodes

Method for testing $cyctime:

After the instance start to run, right-click the node and select View Node Attribute. Check whether the scheduling time is the time at which the instance is run periodically.

The value of the parameter in Running Parameter is replaced with the scheduling time minus 1 hour.

$jobid: The ID of the workflow to which a node belongs. Example: jobid=$jobid.

$nodeid: The ID of a node. Example: nodeid=$nodeid.

$taskid: The ID of a node, that is, the ID of a node instance. Example: taskid=$taskid.

$gmtdate: The current date in the format of yyyymmdd. The value of this parameter is the current date by default. During data patching, the value of gmtdate that is imported is the business date plus 1.

For example, the code of a MaxCompute SQL node includes pt=${datetime}, and the parameter configured for the node is datetime=$gmtdate. When the node is run on July 22, 2017, $gmtdate is replaced with pt=20170722.