reqrate.R

#!/usr/bin/env Rscript 
#
# Usage: $0 <datafile>
#
# Expected data file format: t lt ts s lb rc rm tn dt by
#

myspan = 0.1
myargs <- commandArgs(TRUE)
file <- myargs[1]

d <- read.table (file, header=TRUE)

## Order by timestamp so we can get meaningful iats
d <- d[order(d$ts),]

# Inter-arrival time
v = numeric (length(d$ts))
v[1] = 1
for (i in 2:length(d$ts)) { v[i] = d$ts[i] - d$ts[i-1] + 1 }
d$v <- v

# Main Plot
image = paste(file, ".png", sep="")
png (image, width=960, height=480)
tsmin = min (d$ts)
ymax=1000*60*(1/mean(d$v)+1/sd(d$v))
palette <- rainbow (nlevels(d$lb)+1)
d.lo <- loess (d$v ~ d$ts, span=myspan)

# Total
plot ((d$ts-tsmin)/1000, 1000*60/predict(d.lo, d$ts), type="l", ylab="req/min", xlab="seconds", main="Request Rate", col=palette[1], ylim=c(0,ymax))
legend("topright", c("total", levels(d$lb)), col=palette, lty=1, cex=0.75)

# Labels
pindex = 2;
palette <- rainbow (nlevels(d$lb))
for (label in levels(d$lb))
  {
    print (label)
    a <- subset(d, lb==label)
    v = numeric (length(a$ts))
    v[1] = 1
    for (i in 2:length(a$ts)) { v[i] = a$ts[i] - a$ts[i-1] + 1 }
    a$v <- v
    a.lo <- loess (a$v ~ a$ts, span=myspan)
    lines ((a$ts-tsmin)/1000, 1000*60/predict(a.lo, a$ts), col=palette[pindex])
    rm(a)
    rm(v)
    pindex = pindex+1 
  }

grid()
dev.off()
print (paste("Request rate plot written to file", image))