Sometimes, when I execute the Chrome inside a docker container I receive the error below:

selenium.common.exceptions.WebDriverException: Message: unknown error: Chrome failed to start: crashed

It is caused because Chrome uses the /dev/shm to share memory and the docker, by default, set 64MB for this partition.

Here, I will describe how to reproduce this error and how to resolve it.

How to reproduce

To reproduce this error, we need to create a docker image with chrome and python. Then, I created this Dockerfile which uses a multi-stage build to install the chrome and the python.

I’m learning computer vision and I’m using the Opencv and Python to write algorithms in this field of computer science. This field is very interesting because it involves computer science and math and also, it is necessary to have good ideas to solve problems.

Here, I will show my first algorithm in computer vision. It is to identifies paragraphs in a text image. It consider that the image have a white background and that the characters have a black color.

I wrote a list of operational research resource which contains many name of books, events, groups, solvers and teachers. I publish this list here. It is a github’s repository and you can help to update :-)

I wrote it based on the list, wrote by Avelino, about resources for go programming language.

Callbacks in Cplex

I used LazyConstraintCallback to implement a Branch and Cut algorithm with CPLEX, but when I implemented and run this algorithm, it was very slow if I compare it with its version that doesn’t use callbacks in Cplex. The reason is because ControlCallback(LazyConstraintCallback is a ControlCallback) switch Cplex to sequential mode by default and turn off dynamic search. I wrote this post, because I didn’t find this information in Cplex’s documentation, I only found it in this technical forum.