akumulid process crashed after executing query api

[webfolderio]

Hi,

Akumuli process crashed with the following test case.

1) Create an empty database

akumulid --init
akumulid --create

2) Write the datapoint to Akumuli via tcp port

echo +cpu.usage location=xyz\r\n:1574238775394000000\r\n:10\r\n | netcat localhost 8282

3) Query the datapoint

 curl --header "Content-Type: application/json" --request POST --data '{"select":"cpu.usage","range":{"from":"20191110T113255.72","to":"20191130T113255.72"},"group-by-tag":["location"]}' http://localhost:8181/api/query

Akumuli was abnormally crashed after the step 3 with following error message:

Aborted (core dumped)

OS: Ubuntu 18.04.3
Akumuli version: 0.8.72 (installed from deb package)

[Lazin]

Hi,
The first problem is the use of "echo" command. It sends "\r\n" literally, like sequence of four character, without escaping. It can be fixed by switching to printf command:

printf "+cpu.usage location=xyz\n1574238775394000000\n:10\n" | netcat localhost 8282

It can be easily fixed.

The second problem is on akumulis's side. The ill-formed write sequence can create empty time-series without any data-points inside. This empty time-series can make some queries fail. This should be fixed soon. I'll keep this issue open as long as it's not fixed.