Log Reader

Overview

Plug-in Notes:

Allows only System Administrators or members of the Designers group to access log data.
Does not load files outside the logs directory or files that do not end in .log.* or .csv.*.
On multi-application-server environments, logs will only be shown from a single application server.
Custom headers can be specified as an optional parameter. This is meant to be used for .csv files that don't contain a header.

Key Features & Functionality

The Appian Log Reader Plug-in contains functionality to:

Read files in the Appian /log folder (.csv or .log) and return them as structured data
Aggregate data from a .csv file
Serve as the source for a service-backed record for viewing logs
The Log Reader application provided with the download demonstrates a service-backed record for viewing logs, as well as reports on specific log files. Administrators can view reports on system health over time, including design best practices, system load, and database performance. The application also contains a process that checks details from system.csv and alerts administrators if memory or CPU utilization exceeds a threshold.
Tail a log file with tailcsv and taillog. Note that tail is an expensive operation which is optimized for reading the last few lines of a large log file. It's not advisable to tail the entire log file from the end to the beginning. However, tail will perform much better than the other log functions when reading the last few lines from a very large log file. Use the batch size and timestamp filters to limit the number of lines read by the tailcsv and taillog functions.
Takes a line of text in CSV format and returns a text array

Mark Talbot over 3 years ago in reply to Mike Schmitt

I've added a function that reads the CSV in reverse. Please see if this works for your use case. Note that reading a CSV in reverse is less efficient if you are going to read the whole file than it would be if you read it normally. However, reading the CSV in reverse is more efficient for large files if you are only reading a few lines at a time.
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Appian AppMarket over 3 years ago
v2.1.1 Release Notes
- Additional log functions which start reading from the end of the file
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roopav569 over 4 years ago

Hi,

I am trying to access rdbms-audit.log.yyyy.MM.dd log which is working fine for active version. The rdbms-audit.log.yyyy-MM-dd log rotates every 10MB and change file name as rdbms-audit.log.yyyy.MM.dd.versionNo. The current version of log reader is not able to recognize this new filename and no data are fetched from it.

Do we have any resolution or workaround for it ?
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Sam Zacks over 4 years ago in reply to Mike Schmitt

That is my end goal, yes.
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Mike Schmitt over 4 years ago in reply to Sam Zacks

Sam Zacks - do you mean a fix to the plug-in? That seems like it would be useful, since otherwise any future alterations to the columns of a log file will seemingly have the same "breaking" effect.
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Sam Zacks over 4 years ago in reply to Mike Schmitt

You're correct about this - I understand the issue is when there are inconsistent column sets. I'm continuing to investigate changes and trying to reproduce so that I can prove out a fix.
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Mike Schmitt over 4 years ago in reply to phorning

phorning - I had Appian Support deprecate the existing design_errors.csv files across all my environments, such that a new file has been created as of a few days ago, so that there is now a consistent number of columns across all rows. Per my expectation, the log reader query now works fine.
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Mike Schmitt over 4 years ago in reply to Sam Zacks

Sam Zacks - for further clarification: I've had Appian Support deprecate the existing design_errors.csv in all my environments so that they can start over with consistent columns in all rows, and the log reader query now works fine, as I'd expected.
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Mike Schmitt over 4 years ago in reply to Sam Zacks

Sam Zacks - also, I wasn't notified of your reply until just now when someone clicked "like" on my top comment. I suggest when replying to these you directly tag people and/or click "like" on the comment you're replying to. It seems to me that Community settings should be refined such that people are notified of replies here.
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Mike Schmitt over 4 years ago in reply to Sam Zacks

Sam Zacks - your design_errors.csv file would (i presume) need to have some rows in it with the older version of the column set. What do you see when you look?
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