Keep last 7 days in nlog - nlog

Question

I want to keep last 7 days of files using nlog, but for some reason the following configuration in target=LogToShare is keeping only the latest file:
<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<variable name="WorkflowLoggingDirectory" value="${specialfolder:folder=LocalApplicationData}/Logs" />
<variable name="LogSharedFolder" value="\\myserver\logs" />
<rules>
<logger name="WorkflowLogging" writeTo="LogToShare" />
<logger name="WorkflowLogging" writeTo="WorkflowLogFiles" final="true" />
<logger minLevel="Info" writeTo="EventLog" />
</rules>
<targets>
<target type="File"
name="LogToShare"
layout="${time} ${level} ${message}"
fileName="${LogSharedFolder}\${machinename}_${shortdate}.log"
archiveFileName="${LogSharedFolder}\${machinename}_${shortdate}.{#}.log"
archiveEvery="Day"
archiveNumbering="Rolling"
maxArchiveFiles="7"
keepFileOpen="true"
openFileCacheTimeout="5"
concurrentWrites="true"
encoding="utf-8"
writeBom="true" />
<target type="File" name="WorkflowLogFiles" fileName="${WorkflowLoggingDirectory}/${shortdate}_Execution.log" layout="${time} ${level} ${message}" keepFileOpen="true" openFileCacheTimeout="5" concurrentWrites="true" encoding="utf-8" writeBom="true" />
<target type="EventLog" name="EventLog" layout="${processname} ${assembly-version} ${newline}${message}" source="UiPath" log="Application" />
</targets>
</nlog>
The files in \\myserver\logs that are kept are only the files from the current day:
machine1_2020-08-09.log
machine2_2020-08-09.log
machine3_2020-08-09.log
machine4_2020-08-09.log
Tomorrow, the files that I will get are:
machine1_2020-08-10.log
machine2_2020-08-10.log
machine3_2020-08-10.log
machine4_2020-08-10.log
And the files from 2020-08-09 will be removed.
I'm using NLog v4.3.9. How can I keep the last 7 days of log?

Answer 1

When using NLog 4.5 (or newer) then you can do this:
<target type="File"
name="LogToShare"
layout="${time} ${level} ${message}"
fileName="${LogSharedFolder}/${machinename}_${shortdate}.log"
maxArchiveFiles="7"
keepFileOpen="true"
openFileCacheTimeout="5"
concurrentWrites="true"
encoding="utf-8"
writeBom="true" />
When using older NLog versions, then you can try this:
<target type="File"
name="LogToShare"
layout="${time} ${level} ${message}"
fileName="${LogSharedFolder}/${machinename}_${date:format=yyyy-MM-dd}.log"
archiveFileName="${LogSharedFolder}/${machinename}_{#}.log"
archiveDateFormat="yyyy-MM-dd"
archiveNumbering="Date"
archiveEvery="Year"
maxArchiveFiles="7"
keepFileOpen="true"
openFileCacheTimeout="5"
concurrentWrites="true"
encoding="utf-8"
writeBom="true" />
Explanation of why the extra parameters are needed:
archiveFileName - Using {#} allows the archive cleanup to generate proper file wildcard.
archiveDateFormat - Must match the ${date:format=} of the fileName (So remember to correct both date-formats, if change is needed)
archiveNumbering=Date - Configures the archive cleanup to support parsing of filenames as dates.
archiveEvery=Year - Activates the archive cleanup, but also the archive file operation. Because the configured fileName automatically ensures the archive file operation, then we don't want any additional archive operations (Ex. avoiding generating extra empty files at midnight).
maxArchiveFiles - How many archive files to keep around.