Suhas Hegde 2017-10-25
The following R code were run on a single node Apache spark cluster to aggregate the required results. The process roughly follows the below mentioned sequence of steps.
- Set up a Spark cluster back end
- Read and Parse the Weblog file into the cluster based file system instead of memory(RAM)
- Find cumulative frequency counts for each of the required parameters/columns("host", "request", "HTTP_reply")
# load the required libraries
library(readr)
library(dplyr)
library(ggplot2)
library(sparklyr)
library(magrittr)
library(DBI)
# configure the spark cluster
config <- spark_config()
config$spark.executor.cores <- 2
config$spark.executor.memory <- "4G"
# set up a local spark cluster
sc <- spark_connect(master = "local", config = config)
# create a vector to hold column names and another vector to hold the column
# types being read into the spark table
column_names <- c("host", "drop1", "drop2", "timestamp", "request", "HTTP_reply",
"reply_size")
column <- cols(host = "c", drop1 = "-", drop2 = "-", timestamp = "?", request = "c",
HTTP_reply = "i", reply_size = "i")
# read the log file using 'read_log' and then use 'sdf_copy_to' copy it to a
# spark table
read_log(paste(getwd(), "/NASA_access_log_Jul95", sep = ""), col_names = column_names,
col_types = column) %>% sdf_copy_to(sc, ., "web_log", overwrite = TRUE)## # Source: table<web_log> [?? x 5]
## # Database: spark_connection
## host timestamp
## <chr> <chr>
## 1 199.72.81.55 01/Jul/1995:00:00:01 -0400
## 2 unicomp6.unicomp.net 01/Jul/1995:00:00:06 -0400
## 3 199.120.110.21 01/Jul/1995:00:00:09 -0400
## 4 burger.letters.com 01/Jul/1995:00:00:11 -0400
## 5 199.120.110.21 01/Jul/1995:00:00:11 -0400
## 6 burger.letters.com 01/Jul/1995:00:00:12 -0400
## 7 burger.letters.com 01/Jul/1995:00:00:12 -0400
## 8 205.212.115.106 01/Jul/1995:00:00:12 -0400
## 9 d104.aa.net 01/Jul/1995:00:00:13 -0400
## 10 129.94.144.152 01/Jul/1995:00:00:13 -0400
## # ... with more rows, and 3 more variables: request <chr>,
## # HTTP_reply <int>, reply_size <int>
src_tbls(sc)## [1] "web_log"
# task 1 using 'host' as the key find out the cumulative frequency of each
# 'host'
tbl(sc, "web_log") %>% group_by(host) %>% summarise(freq = n()) %>% arrange(desc(freq))## # Source: lazy query [?? x 2]
## # Database: spark_connection
## # Ordered by: desc(freq)
## host freq
## <chr> <dbl>
## 1 piweba3y.prodigy.com 17572
## 2 piweba4y.prodigy.com 11591
## 3 piweba1y.prodigy.com 9868
## 4 alyssa.prodigy.com 7852
## 5 siltb10.orl.mmc.com 7573
## 6 piweba2y.prodigy.com 5922
## 7 edams.ksc.nasa.gov 5434
## 8 163.206.89.4 4906
## 9 news.ti.com 4863
## 10 disarray.demon.co.uk 4353
## # ... with more rows
tbl(sc, "web_log") %>% group_by(host) %>% summarise(freq = n()) %>% top_n(n = 30,
wt = freq) %>% collect() %>% {
(ggplot(data = .) + geom_bar(aes(host, freq), stat = "identity", fill = "red2",
alpha = 0.65) + coord_flip())
}
# task 2 using 'request' as the key find out the cumulative frequency of
# each 'request'
tbl(sc, "web_log") %>% group_by(request) %>% summarise(freq = n()) %>% arrange(desc(freq))## # Source: lazy query [?? x 2]
## # Database: spark_connection
## # Ordered by: desc(freq)
## request freq
## <chr> <dbl>
## 1 GET /images/NASA-logosmall.gif HTTP/1.0 110679
## 2 GET /images/KSC-logosmall.gif HTTP/1.0 89355
## 3 GET /images/MOSAIC-logosmall.gif HTTP/1.0 59967
## 4 GET /images/USA-logosmall.gif HTTP/1.0 59514
## 5 GET /images/WORLD-logosmall.gif HTTP/1.0 58997
## 6 GET /images/ksclogo-medium.gif HTTP/1.0 58411
## 7 GET /images/launch-logo.gif HTTP/1.0 40780
## 8 GET /shuttle/countdown/ HTTP/1.0 40132
## 9 GET /ksc.html HTTP/1.0 39830
## 10 GET /images/ksclogosmall.gif HTTP/1.0 33528
## # ... with more rows
tbl(sc, "web_log") %>% group_by(request) %>% summarise(freq = n()) %>% top_n(n = 30,
wt = freq) %>% collect() %>% {
(ggplot(data = .) + geom_bar(aes(request, freq), stat = "identity", fill = "palegreen4",
alpha = 0.65) + coord_flip())
}
# task 3 using 'HTTP_reply' as the key find out the cumulative frequency of
# each 'HTTP_reply'
tbl(sc, "web_log") %>% group_by(HTTP_reply) %>% summarise(freq = n()) %>% arrange(desc(freq))## # Source: lazy query [?? x 2]
## # Database: spark_connection
## # Ordered by: desc(freq)
## HTTP_reply freq
## <int> <dbl>
## 1 200 1701534
## 2 304 132627
## 3 302 46573
## 4 404 10833
## 5 500 62
## 6 403 53
## 7 501 14
## 8 NA 14
## 9 400 5
tbl(sc, "web_log") %>% group_by(HTTP_reply) %>% summarise(freq = n()) %>% collect() %>%
{
(ggplot(data = .) + geom_bar(aes(as.character(HTTP_reply), freq), stat = "identity",
fill = "dodgerblue3", alpha = 0.65) + coord_flip())
}
# Tasks using SQL task1
dbGetQuery(sc, "SELECT HOST, count(host) FREQUENCY FROM
web_log group by host order by count(host) desc LIMIT 10")## HOST FREQUENCY
## 1 piweba3y.prodigy.com 17572
## 2 piweba4y.prodigy.com 11591
## 3 piweba1y.prodigy.com 9868
## 4 alyssa.prodigy.com 7852
## 5 siltb10.orl.mmc.com 7573
## 6 piweba2y.prodigy.com 5922
## 7 edams.ksc.nasa.gov 5434
## 8 163.206.89.4 4906
## 9 news.ti.com 4863
## 10 disarray.demon.co.uk 4353
# task2
dbGetQuery(sc, "SELECT REQUEST, count(REQUEST) frequency FROM
web_log group by REQUEST order by count(REQUEST) desc LIMIT 10")## REQUEST frequency
## 1 GET /images/NASA-logosmall.gif HTTP/1.0 110679
## 2 GET /images/KSC-logosmall.gif HTTP/1.0 89355
## 3 GET /images/MOSAIC-logosmall.gif HTTP/1.0 59967
## 4 GET /images/USA-logosmall.gif HTTP/1.0 59514
## 5 GET /images/WORLD-logosmall.gif HTTP/1.0 58997
## 6 GET /images/ksclogo-medium.gif HTTP/1.0 58411
## 7 GET /images/launch-logo.gif HTTP/1.0 40780
## 8 GET /shuttle/countdown/ HTTP/1.0 40132
## 9 GET /ksc.html HTTP/1.0 39830
## 10 GET /images/ksclogosmall.gif HTTP/1.0 33528
# task3
dbGetQuery(sc, "SELECT HTTP_reply, count(HTTP_reply) frequency FROM
web_log where HTTP_reply = 404 group by HTTP_reply
order by count(HTTP_reply) desc LIMIT 10")## HTTP_reply frequency
## 1 404 10833
# disconnect from the cluster
spark_disconnect(sc)- "sparklyr" - R interface for Apache Spark - R studio
- "NASA-HTTP" - Two month's worth of all HTTP requests to the NASA Kennedy Space Center WWW server in Florida