How to use subprocess.run() to run Hive query?

Question

So I'm trying to execute a hive query using the subprocess module, and save the output into a file data.txt as well as the logs (into log.txt), but I seem to be having a bit of trouble. I've look at this gist as well as this SO question, but neither seem to give me what I need.

Here's what I'm running:

import subprocess
query = "select user, sum(revenue) as revenue from my_table where user = 'dave' group by user;"
outfile = "data.txt"
logfile = "log.txt"

log_buff = open("log.txt", "a")
data_buff = open("data.txt", "w")

# note - "hive -e [query]" would normally just print all the results 
# to the console after finishing
proc = subprocess.run(["hive" , "-e" '"{}"'.format(query)],
                    stdin=subprocess.PIPE,
                    stdout=data_buff,
                    stderr=log_buff,
                    shell=True)

log_buff.close()
data_buff.close()

I've also looked into this SO question regarding subprocess.run() vs subprocess.Popen, and I believe I want .run() because I'd like the process to block until finished.

The final output should be a file data.txt with the tab-delimited results of the query, and log.txt with all of the logging produced by the hive job. Any help would be wonderful.

Update:

With the above way of doing things I'm currently getting the following output:

log.txt

[ralston@tpsci-gw01-vm tmp]$ cat log.txt
Java HotSpot(TM) 64-Bit Server VM warning: Using the ParNew young collector with the Serial old collector is deprecated and will likely be removed in a future release
Java HotSpot(TM) 64-Bit Server VM warning: Using the ParNew young collector with the Serial old collector is deprecated and will likely be removed in a future release
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/y/share/hadoop-2.8.3.0.1802131730/share/hadoop/common/lib/slf4j-log4j12-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/y/libexec/tez/lib/slf4j-log4j12-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.slf4j.impl.Log4jLoggerFactory]

Logging initialized using configuration in file:/home/y/libexec/hive/conf/hive-log4j.properties

data.txt

[ralston@tpsci-gw01-vm tmp]$ cat data.txt
hive> [ralston@tpsci-gw01-vm tmp]$

And I can verify the java/hive process did run:

[ralston@tpsci-gw01-vm tmp]$ ps -u ralston
  PID TTY          TIME CMD
14096 pts/0    00:00:00 hive
14141 pts/0    00:00:07 java
14259 pts/0    00:00:00 ps
16275 ?        00:00:00 sshd
16276 pts/0    00:00:00 bash

But it looks like it's not finishing and not logging everything that I'd like.

you probably meant `log_buff = open(logfile, "a")` and `data_buff = open(outfile, "w")` — Chingiz K., Jun 30 '21 at 22:32

score 1 · Answer 1 · answered Nov 09 '18 at 22:21

So I managed to get this working with the following setup:

import subprocess
query = "select user, sum(revenue) as revenue from my_table where user = 'dave' group by user;"
outfile = "data.txt"
logfile = "log.txt"

log_buff = open("log.txt", "a")
data_buff = open("data.txt", "w")
# Remove shell=True from proc, and add "> outfile.txt" to the command
proc = subprocess.Popen(["hive" , "-e", '"{}"'.format(query), ">", "{}".format(outfile)],
                    stdin=subprocess.PIPE,
                    stdout=data_buff,
                    stderr=log_buff)
# keep track of job runtime and set limit
start, elapsed, finished, limit  = time.time(), 0, False, 60
while not finished:
    try:
        outs, errs = proc.communicate(timeout=10)
        print("job finished")
        finished = True
    except subprocess.TimeoutExpired:
        elapsed = abs(time.time() - start) / 60. 
        if elapsed >= 60:
            print("Job took over 60 mins")
            break 
        print("Comm timed out. Continuing")
        continue

print("done")

log_buff.close()
data_buff.close()

Which produced the output as needed. I knew about process.communicate() but that previously didn't work. I believe the issue was related to not adding an output file with > ${outfile} to the hive query.

Feel free to add any details. I've never seen anyone have to loop over proc.communicate() so I'm skeptical that I might be doing something wrong.

missing `import time` on top – Chingiz K. Jun 30 '21 at 22:30 — Chingiz K., Jun 30 '21 at 22:30

How to use subprocess.run() to run Hive query?

1 Answers1