Shared Concepts and Topics

Alongside-HDFS Execution by Using the SASHDAT Engine

If the grid host is a cluster that houses data that have been distributed by using the SASHDAT engine, then high-performance analytical procedures can analyze those data in the alongside-HDFS mode. The procedures use the distributed computing environment in which an analytic process is collocated with the nodes of the cluster. Data then pass from HDFS to the analytic process on each node of the cluster.

Before you can run a procedure alongside HDFS, you must distribute the data to the cluster. The following statements use the SASHDAT engine to distribute to HDFS the simData data set that was used in the previous two sections:


option set=GRIDHOST="hpa.sas.com";

libname hdatLib sashdat
        path="/hps";

 data hdatLib.simData (replace = yes) ;
     set simData;
 run;

In this example, the GRIDHOST is a cluster where the SAS Data in HDFS Engine is installed. If a data set that is named simData already exists in the hps directory in HDFS, it is overwritten because the REPLACE=YES data set option is specified. For more information about using this LIBNAME statement, see the section "LIBNAME Statement for the SAS Data in HDFS Engine" in the SAS LASR Analytic Server Administration Guide.

The following HPLOGISTIC procedure statements perform the analysis in alongside-HDFS mode. These statements are almost identical to the PROC HPLOGISTIC example in the previous two sections, which executed in single-machine mode and alongside-the-database distributed mode, respectively.

Figure 10 shows the "Performance Information" and "Data Access Information" tables. You see that the procedure ran in distributed mode and that the input data were read in parallel symmetric mode. The numeric results shown in Figure 11 agree with the previous analyses shown in Figure 1, Figure 2, and Figure 5.

Figure 10: Alongside-HDFS Execution Performance Information

The HPLOGISTIC Procedure

Performance Information
Host Nodehpa.sas.com
Execution ModeDistributed
Number of Compute Nodes13
Number of Threads per Node24

Data Access Information
DataEngineRolePath
HDATLIB.SIMDATASASHDATInputParallel, Symmetric


Figure 11: Alongside-HDFS Execution Model Information

Model Information
Data SourceHDATLIB.SIMDATA
Response Variabley
Class ParameterizationGLM
DistributionBinary
Link FunctionLogit
Optimization TechniqueNewton-Raphson with Ridging

Parameter Estimates
ParameterEstimateStandard
Error
DFt ValuePr > |t|
Intercept5.70110.2539Infty22.45<.0001
a 0-0.010200.06627Infty-0.150.8777
a 10....
b 00.71240.06558Infty10.86<.0001
b 10....
c 00.80360.06456Infty12.45<.0001
c 10....
x10.019750.000614Infty32.15<.0001
x2-0.047280.003098Infty-15.26<.0001
x3-0.10170.009470Infty-10.74<.0001


Last updated: July 02, 2020