How to set a fault tolerante channel between nlog and nxlog?

Question

My application uses nlog. It needs to send logs to a nxlog process running in the same host (which I also have control over).

I thought of sending json lines using TCP or UDP from nlog to nxlog. That's a straightforward design but it is not fault tolerant AFAIK. If nxlog goes down momentarily, nlog may even keep retrying but if my app exits at that moment, log messages are lost.

Alternatively I can set nlog file target to write json lines to. It will work as a persisted buffer. Nxlog would read from that file. The problem becomes how to setup file rolling settings. If I don't set rolling, nlog may truncate the file before nxlog can read the last log lines. If I set rolling, nxlog will see the new archived file as a new set of logs and "replay" them generating duplicates.

So, my question is: how do I setup nlog and nxlog to be fault tolerant and prevent duplicates?

score 1 · Answer 1 · answered May 16 '15 at 15:06

1

If you configure nlog to create one log per day, i.e. log files are created with the date in the file name and are not rolled, then nxlog will be able to pick up the files and there won't be duplicates.

answered May 16 '15 at 15:06

b0ti

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I can't keep files forever. Is there a way to automatically delete them? Size may also be a problem. – Igor Gatis May 16 '15 at 17:13
NXLog has a block that can be used to clean up old log files. You can use the built-in functions or some external script called with exec(). – b0ti May 18 '15 at 11:58

score 0 · Accepted Answer · edited Sep 26 '16 at 22:14

I took b0ti's suggestion and came up with:

var file = new FileTarget
{
    FileName = @"C:\Logs\file.log",
    ArchiveFileName = @"C:\Logs\file.{#}.log",

    ArchiveEvery = FileArchivePeriod.Minute,
    ArchiveAboveSize = 2 * 1024 * 1024,  // 2MB.

    ArchiveNumbering = ArchiveNumberingMode.Sequence,
    MaxArchiveFiles = 60,
};

Nxlog watches only the archived file: C:\Logs\file.{#}.log

NLog will add a new file for Nxlog every minute or whenever it becomes large enough (2MB in the example above). That's an acceptable delay in my case.

It keeps 1 hour of logs if my app is not logging much. If it is logging like crazy, history will be shorter but no grater than 122MB (2 + 2 * 60).

How to set a fault tolerante channel between nlog and nxlog?

2 Answers2