Description Usage Arguments Value Author(s) See Also Examples
Within bolts in a RStorm stream the TrackRow
function can be used to store the state of variables at that point during the stream. The TrackRow
function will store values incrementally during the stream. Thus, TrackRow
enables one to store a set of parameter at each event in a Bolt. The current GetTrackNames
function allows to inspect all the tracked objects of a stream by passing the RStorm result object.
1 |
x |
a RStorm result object. |
A list of names of the tracked objects during the stream.
Maurits Kaptein
See Also: TrackRow
, SetHash
, GetHash
, GetTrack
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | # Create a topology with a spout
topology <- Topology(data.frame(x=c(1:10)))
# Add a bolt to the topology
computeSum <- function(x, ...){
sum <- GetHash("sum")
if(is.data.frame(sum)){
x <- sum + (x[1])
}
SetHash("sum", x)
# Track the current state during the stream:
TrackRow("sum", data.frame(x=x))
}
topology <- AddBolt(topology, Bolt(computeSum))
# Run the stream
result <- RStorm(topology)
# Inspect the sums during the stream
GetTrackNames(result)
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