In this document we describe the Brewer diagnostic system. All the code is available in the rbcce subversion repository.

The main component is a parser. This parser extracts information from the B and D files and then stores usefull information in status files and to database as well.

In order to have a good indicator of the brewer's status, the next error types must be detected and then they should be condensed in a sets of bits that can be decoded again. Every single error type have associated a mask that set or unset a single bit in this status bit sets. In the beginning of the proyect we need 4 bytes to represent 32 error types.

• Number of type error limitations: The more error we detect the more bits we need. At some point we will be run out error types and we need another byte to archive the upgrade. In order to avoid this problem we added a unique error code integer to have more than 2^64 error types. In the future we can get rid of this sets of bits because this requirement is a limitation itself.

There are another set of test that should be done comparing a parsed value against a threshold. This threshold could be obtained from 3 different ways per each test.

1. default value: in the database we will store a value +- thereshold.
2. brewer dependant value: in the database we will store a value +- threshold per brewer.
3. brewer dependant from config: in the database we will get a value from the brewer config +- a threshold.

Additionally to the information extracted stated above, we need to extract more information because we need to check if the error is a false positive in the sources of error. In addition, we could need create complex database querys to make a more accurate diagnosis.

The information that we extract from the files will be described below.

The following errors: UTC date failure, Julian date failure and Time failure, are difficult to extract. The only way to know the status of the remote clock is with the files' modification time. When we are copying those files to the local machine, we lose the modification time and its imposible to check if the remote clock is shift.

Proposed solution: We need to create a mecanism that allows the status tool to pool the remote clock in order to check if is synced.

This problem is hard to parse because in the B or D files appears to be a user command. This means that the user can type a error message in their own language. Sometimes we found the message in english but almost the majority of times we found this messages in a different language which is imposible to parse.

1. Every 15 minutes the eubrewnet system pools the B and D files from the brewers.
2. The diagnostic tool parser receives it as input.
3. The output is written to database and files.
4. The Eubrewnet webpage shows the information extracted before.

The front end consist of two views, the main view that is the brewer overview and the detailed view.

When the users get into the frontpage, they can see a map with the status of the brewers. A code of colours states the status of the brewer. green means OK, yellow means WARNING, orange means ERROR, red means CRITICAL, grey means no data since the last 24 hours and finally black means no data since the last 48 hours.

example:

When the user clicks in a brewer, the user will be redirected to the details of the brewer. In the Brewer Status section we can see a list of original messages taken from D or B files explaining the status of the brewer.

The next example shows a brewer in a OK status.

The next example shows a brewer with several CRITICAL problems.

The entry point of the diagnosis tool is monitor.py. The pseudo code of monitor.py is the following:

1. create a list of path to posible files
2. test if this file exist
3. parse the file
4. write the status on file
5. write the status on database

The third item on the previous list is the parser itself and the file that contain the parser is parseSingleFile.py

parseSingleFile is a parent class of parseDFile.py and parseBFile.py. It contains many functionality to handle files and database access.

ParseBFile.py and ParseDFile.py contains an abstract function called parse_lines() that takes a list of lines of a given file and then creates a list of error. The pseudocode is the following:

1. iterate over all lines of a file
   1. iterate over all error types
      1. if the line contains a specific string
         1. create new error
         2. push this new error in the errorList grouping by error code.