publish_DSC_via_WebService: Publish a Data Stream Clustering Task via a Web Service

In streamConnect: Connecting Stream Mining Components Using Sockets and Web Services

Publish a Data Stream Clustering Task via a Web Service

Description

Uses the package plumber to publish a data stream task as a web service.

Usage

publish_DSC_via_WebService(
  dsc,
  port,
  task_file = NULL,
  serializer = "csv",
  serve = TRUE,
  background = TRUE,
  debug = FALSE
)

Arguments

dsc	A character string that creates a DSC.
port	port used to serve the task.
task_file	name of the plumber task script file.
serializer	method used to serialize the data. By default csv (comma separated values) is used. Other methods are json and rds (see plumber::serializer_csv).
serve	if TRUE, then a task file is written and a server started, otherwise, only a plumber task file is written.
background	logical; start a background process?
debug	if TRUE, then the service is started locally and a web client is started to explore the interface.

Details

The function writes a plumber task script file and starts the web server to serve the content of the stream using the endpoints

• GET ⁠/info⁠

• POST ⁠/update⁠ requires the data to be uploaded as a file in csv format (see Examples section).

• GET ⁠/get_centers⁠ with parameter type (see stream::get_centers()).

• GET ⁠/get_weights⁠ with parameter type (see stream::get_weights()).

Supported serializers are csv (default), json, and rds.

APIs generated using plumber can be easily deployed. See: Hosting. By setting a task_file and serve = FALSE a plumber task script file is generated that can deployment.

Value

a processx::process object created with callr::r_bg() which runs the plumber server in the background. The process can be stopped with rp$kill() or by killing the process using the operating system with the appropriate PID. rp$get_result() can be used to check for errors in the server process (e.g., when it terminates unexpectedly).

See Also

Other WebService: DSC_WebService(), DSD_ReadWebService(), publish_DSD_via_WebService()

Other dsc: DSC_WebService()

Examples

# find a free port
port <- httpuv::randomPort()
port

# Deploy a clustering process listening for data on the port
rp1 <- publish_DSC_via_WebService("DSC_DBSTREAM(r = .05)", port = port)
rp1

# look at ? DSC_WebService for a convenient interface. 
# Here we we show how to connect to the port and send data manually.
library(httr)

# the info verb returns some basic information about the clusterer.
resp <- RETRY("GET", paste0("http://localhost:", port, "/info"))
d <- content(resp, show_col_types = FALSE)
d

# create a local data stream and send it to the clusterer using the update verb.
dsd <- DSD_Gaussians(k = 3, d = 2, noise = 0.05)

tmp <- tempfile()
stream::write_stream(dsd, tmp, n = 500, header = TRUE)
resp <- POST(paste0("http://localhost:", port, "/update"), 
  body = list(upload = upload_file(tmp)))
unlink(tmp)
resp

# retrieve the cluster centers using the get_centers verb
resp <- GET(paste0("http://localhost:", port, "/get_centers"))
d <- content(resp, show_col_types = FALSE)
head(d)

plot(dsd, n = 100)
points(d, col = "red", pch = 3, lwd = 3)

# kill the process.
rp1$kill()
rp1

# Debug the interface (run the service and start a web interface)
if (interactive())
  publish_DSC_via_WebService("DSC_DBSTREAM(r = .05)", 
         port = port, debug = TRUE)

streamConnect documentation built on June 22, 2024, 9:55 a.m.