# Logstash does nothing for valid json input
**URL:** https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595
**Category:** Logstash
**Created:** [March 7, 2017, 4:00am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595 "2017-03-07T04:00:53Z")
**Posts on this page:** 10
**Page:** 1
### Author:  [@tushartyagi](https://discuss.elastic.co/u/tushartyagi)
#### Post date: [March 7, 2017, 4:00am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595/1 "2017-03-07T04:00:53Z")
Hi,
Since yesterday I am trying to work with logstash but I am not able to make much progress.
I have some sentiment data in json which I am trying to read in. If there is a syntax error in the file, or if I use "json" codec for newline delimited file, then I get loads of errors in the stdout. This shows that logstash is at-least trying to read the file.
If I have a single-line json, and I use the codec "json", then I see absolutely nothing. Just some configuration info is printed and the app exits.
Here is my config file:
```auto
input {
file {
path => "e:\json_data.json"
codec => "json"
sincedb_path => "NUL"
start_position => "beginning"
}
}
output {
stdout {
codec => "rubydebug"
}
}
```
Here is the data I want to read-in. I remove all the spaces and turn the file into a non-newline delimited json before passing the data
```auto
[
{
"status": "OK",
"docSentiment": {
"score": "-0.831986",
"type": "negative"
},
"language": "english",
"docEmotions": {
"anger": "0.5748",
"joy": "0.046363",
"fear": "0.041051",
"sadness": "0.036716",
"disgust": "0.399636"
}
}
]
```
For the interested, here's the data in one line:
```auto
[{"status":"OK","totalTransactions":"2","docSentiment":{"score":"-0.831986","type":"negative"},"language":"english","docEmotions":{"anger":"0.5748","joy":"0.046363","fear":"0.041051","sadness":"0.036716","disgust":"0.399636"}}]
```
What I am not able to understand is that using `stdin { codec => "json" }` and pasting the data on the console works fine. But redirecting the correct data does nothing. Again, passing the errorneous data throws a lots of errors.
Since I am not using `elasticsearch` as the `output`, I at least want to see how the data is being parsed by the application.
---
### Author:  [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)
#### Post date: [March 7, 2017, 6:14am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595/2 "2017-03-07T06:14:13Z")
Try the json\_lines codec instead. You're going to have to pass the whole JSON object on a single line.
---
### Author:  [@tushartyagi](https://discuss.elastic.co/u/tushartyagi)
#### Post date: [March 7, 2017, 6:46am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595/3 "2017-03-07T06:46:59Z")
The documentation says that `json_codec` should be used for newline delimited lines, and I am sending json as a single line w/o newlines.
Anyhow, tried with json\_codec and still I see no output.
---
### Author:  [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)
#### Post date: [March 7, 2017, 6:53am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595/4 "2017-03-07T06:53:03Z")
> and I am sending json as a single line w/o newlines.
Exactly, but if you have multiple JSON objects they will be separated by newline characters and therefore the json\_lines codec is a good choice.
Your problem is most likely that you're not setting `start_position => beginning` for your file input, so Logstash is tailing your file.
---
### Author:  [@tushartyagi](https://discuss.elastic.co/u/tushartyagi)
#### Post date: [March 7, 2017, 7:04am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595/5 "2017-03-07T07:04:07Z")
I am using `start_position => "beginning"` (with quotes) but have not listed it here ☹
Let me change the config above to reflect that.
---
### Author:  [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)
#### Post date: [March 7, 2017, 7:05am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595/6 "2017-03-07T07:05:53Z")
Increase the log level with `--verbose` or even `--debug`to get more about what's happening.
---
### Author:  [@tushartyagi](https://discuss.elastic.co/u/tushartyagi)
#### Post date: [March 7, 2017, 7:10am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595/7 "2017-03-07T07:10:14Z")
It's sort of an infinite loop of:
```auto
12:38:04.351 [Ruby-0-Thread-10: D:/programs/logstash/logstash-core/lib/logstash/pipeline.rb:538] DEBUG logstash.pipeline - Pushing flush onto pipeline
12:38:04.743 [[main]
### Author:  [@magnusbaeck](https://discuss.elastic.co/u/magnusbaeck)
#### Post date: [March 7, 2017, 7:23am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595/8 "2017-03-07T07:23:03Z")
The last two lines are interesting. Have you double-checked that the file listed there actually exists and is accessible to Logstash? Have you tried using forward slashes instead of backslashes in the path?
---
### Author:  [@tushartyagi](https://discuss.elastic.co/u/tushartyagi)
#### Post date: [March 7, 2017, 7:28am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595/9 "2017-03-07T07:28:03Z")
Putting forward slashes changes the globbed\_files output to
```auto
12:55:36.390 [[main]
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [April 4, 2017, 7:28am UTC](https://discuss.elastic.co/t/logstash-does-nothing-for-valid-json-input/77595/10 "2017-04-04T07:28:10Z")
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