JuliaGateway

Interface to Julia programming language for InterSystems IRIS. Execute Julia code and more from InterSystems IRIS.
This projects brings you the power of Julia right into your InterSystems IRIS environment:

• Execute arbitrary Julia code
• Seamlessly transfer data from InterSystems IRIS into Julia
• Build intelligent Interoperability business processes with Julia Interoperability Adapter

ML Toolkit user group

ML Toolkit user group is a private GitHub repository set up as part of InterSystems corporate GitHub organization. It is addressed to the external users that are installing, learning or are already using ML Toolkit components. To join ML Toolkit user group, please send a short e-mail at the following address: MLToolkit@intersystems.com and indicate in your e-mail the following details (needed for the group members to get to know and identify you during discussions):

• GitHub username
• Full Name (your first name followed by your last name in Latin script)
• Organization (you are working for, or you study at, or your home office)
• Position (your actual position in your organization, or “Student”, or “Independent”)
• Country (you are based in)

Installation

1. Install Julia 1.4.0 64 bit (other Julia versions are untested). Follow OS specific instructions for installing Julia (Windows, Linux, Mac).
2. Download latest JuliaGateway release and unpack it.
3. From the InterSystems IRIS terminal, load ObjectScript code. To do that execute: do $system.OBJ.ImportDir("/path/to/unpacked/juliagateway","*.cls","c",,1)) in Production (Ensemble-enabled) namespace. In case you want to Production-enable namespace call: write ##class(%EnsembleMgr).EnableNamespace($Namespace, 1).
4. Place callout DLL/SO/DYLIB in the bin folder of your InterSystems IRIS installation. Library file should be placed into a path returned by write ##class(isc.julia.Callout).GetLib().

Windows

6. Check that your JULIA_HOME environment variable points to Julia 1.4.0.
7. Check that your SYSTEM PATH environment variable has:

• %JULIA_HOME%\bin variable (or directory it points to)

8. Restart InterSystems IRIS.
9. In the InterSystems IRIS Terminal, run:

• write $SYSTEM.Util.GetEnviron("JULIA_HOME") and verify it prints out the directory of Julia installation
• write $SYSTEM.Util.GetEnviron("PATH") and verify it prints out the bin directory of Julia installation

Linux and Mac

6. Set LibPath configuration parameter to the value of $JULIA_HOME/lib (if you installed to /tmp/julia, set LibPath=/tmp/julia/lib).
7. Restart InterSystems IRIS.

Post installation (Windows, Mac, Linux)

After installation you’ll need these packages. In OS bash run:

import Pkg;
Pkg.add(["JSON", "CSV", "DataFrames"])
using JSON, CSV, DataFrames

Docker

1. To build docker image:

• Copy iscjulia.so into repository root (if it’s not there already)
• Execute in the repository root docker build --force-rm --tag intersystemsdc/irisjulia:latest . By default the image is built upon store/intersystems/iris-community:2019.4.0.383.0 image, however you can change that by providing IMAGE variable. To build from InterSystems IRIS execute: docker build --build-arg IMAGE=store/intersystems/iris:2019.4.0.383.0 --force-rm --tag intersystemsdc/irisjulia:latest .

2. To run docker image execute (key is not needed for Community based images):

docker run -d \
  -p 52773:52773 \
  -v /<HOST-DIR-WITH-iris.key>/:/mount \
  --name iris \
  intersystemsdc/irisjulia:latest \
  --key /mount/iris.key \

3. For terminal access execute: docker exec -it iris iris session iris.
4. Access SMP with SuperUser/SYS or Admin/SYS user/password.
5. To stop container execute: docker stop iris && docker rm --force iris.

Use

1. Call: set sc = ##class(isc.julia.Callout).Setup() once per systems start (add to ZSTART: docs, sample routine available in rtn folder).
2. Initialize Julia once per process start: set sc = ##class(isc.julia.Callout).Initialize()
3. Call main method (can be called many times, context persists): write ##class(isc.julia.Main).SimpleString(code, .result)
4. Call: set sc = ##class(isc.julia.Callout).Finalize() to free Julia context.
5. Call: set sc = ##class(isc.julia.Callout).Unload() to free callout library.

set sc = ##class(isc.julia.Callout).Setup() 
set sc = ##class(isc.julia.Callout).Initialize()
set sc = ##class(isc.julia.Main).SimpleString("sqrt(4)", .result)
write result
set sc = ##class(isc.julia.Callout).Finalize()
set sc = ##class(isc.julia.Callout).Unload()

Terminal API

Generally the main interface to Julia is isc.julia.Main. It offers these methods (all return %Status), which can be separated into three categories:

• Code execution
• Data transfer
• Auxiliary

Code execution

These methods allow execution of arbitrary Julia code:

• ImportModule(module) - import module.
• SimpleString(code, .result) - execute code for cases where both code and result are less than $$$MaxStringLength in length.
• ExecuteCode(code, variable, .result) - execute code (it may be a stream or string), optionally set code into variable.

Data Transfer

Transfer data into and from Julia.

Julia -> InterSystems IRIS

• GetVariable(variable, serialization, .stream, useString) - get serialization of variable in stream. If useString is 1 and variable serialization can fit into string then string is returned instead of the stream.

InterSystems IRIS -> Julia

• ExecuteQuery(query, variable, type, namespace) - create DataFrame from sql query and set it into variable. isc.julia package must be available in namespace (Available type is DataFrame).

Auxiliary

Support methods.

• GetVariableInfo(variable, serialization, .defined, .type, .length) - get info about variable: is it defined, type and serialized length.
• GetVariableDefined(variable, .defined) - is variable defined.
• GetVariableType(variable, .type) - get variable FQCN.

Possible Serializations:

• string - Serialization by string() function
• json - Serialization by JSON module

Shell

To open Julia shell: do ##class(isc.julia.util.Shell).Shell(). To exit press enter.

In rtn folder zj command example is also available. Import into %SYS namespace.

Interoperability adapter

Interoperability adapter isc.julia.ens.Operation offers ability to interact with Julia process from Interoperability productions. Currently three requests are supported:

• Execute Julia code via isc.julia.msg.ExecutionRequest. Returns isc.julia.msg.ExecutionResponse with requested variable values
• Execute Julia code via isc.julia.msg.StreamExecutionRequest. Returns isc.julia.msg.StreamExecutionResponse with requested variable values. Same as above, but accepts and returns streams instead of strings.
• Set dataset from SQL Query with isc.julia.msg.QueryRequest. Returns Ens.Response.

Check request/response classes documentation for details.

Settings:

• Initializer - select a class implementing isc.julia.init.Abstract. It can be used to load functions, modules, classes and so on. It would be executed at process start.

Test Business process

1. Execute in OS bash:

julia <repo-dir>\install.jl

2. In InterSystems IRIS terminal execute: write ##class(isc.julia.test.AMES).Import() to load the dataset.
3. Start isc.julia.test.Production production.
4. Send empty Ens.Request message to the isc.julia.test.Process.

Variable substitution

All business processes inheriting from isc.julia.ens.ProcessUtils can use GetAnnotation(name) method to get value of activity annotation by activity name. Activity annotation can contain variables which would be calculated on ObjectScript side before being passed to Julia. This is the syntax for variable substitution:

• ${class:method:arg1:...:argN} - execute method
• #{expr} - execute ObjectScript code

Example: save(r'#{process.WorkDirectory}SHOWCASE${%PopulateUtils:Integer:1:100}.png')

In this example:

• #{process.WorkDirectory} returns WorkDirectory property of process object which is an instance of the current business process.
• ${%PopulateUtils:Integer:1:100} calls Integer method of %PopulateUtils class passing arguments 1 and 100, returning random integer in range 1...100.

Unit tests

To run tests execute:

set repo = ##class(%SourceControl.Git.Utils).TempFolder()
set ^UnitTestRoot = ##class(%File).SubDirectoryName(##class(%File).SubDirectoryName(##class(%File).SubDirectoryName(repo,"isc"),"julia"),"unit",1)
set sc = ##class(%UnitTest.Manager).RunTest(,"/nodelete")

ZLANGC00

Install ZLANG routine from rtn folder to add zj command:

zj "sqrt(2)"
zj

Argumentless zj command opens Julia shell.

Limitations

There are several limitations associated with the use of JuliaGateway.

1. Pkg is not supported on Windows.
2. Variables. Do not use these variables: zzz* variables. Please report any leakage of these variables. System code should always clear them.
3. Functions Do not redefine zzz*() functions.

Development

Development of ObjectScript is done via cache-tort-git in UDL mode.
Development of C code is done in Eclipse.

Commits

Commits should follow the pattern: module: description issue. List of modules:

• Callout - C and ObjectScript callout interface in isc.julia.Callout.
• API - terminal API, mainly isc.julia.Main.
• Interoperability - support utilities for Interoperability Business Processes.
• Tests - unit tests and test production.
• Docker - containers.
• Docs - documentation.

Building

Windows

1. Install MinGW-w64 you’ll need make and gcc.
2. Rename mingw32-make.exe to make.exe in mingw64\bin directory.
3. Set GLOBALS_HOME environment variable to the root of InterSystems IRIS installation.
4. Set JULIA_HOME environment variable to the root of Julia installation.
5. Open MinGW bash (mingw64env.cmd or mingw-w64.bat).
6. In <Repository>\c\ execute make.

Linux / Mac

1. Install Julia.
2. Install: apt install build-essential (for Mac install gcc compiler and make).
3. Set GLOBALS_HOME environment variable to the root of InterSystems IRIS installation.
4. Set JULIA_HOME environment variable to the root of Julia installation.
5. In <Repository>/c/ execute make.