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Tableau creates three log files, though only the file named "Log.txt" or "Log_n.txt" retains its same function, the others "hyperd.txt" and "tabprotosrv.txt" change their function slightly depending on your data source:
| All data sources | Log.txt | The basic log file, this contains all actions regarding the Tableau dev environment relating to graphics rendering, from the layout of the object panes, to how data is drawn on the page. This file has less use in error tracing and query performance optimisation although, it we can use the information captured in this log to determine exactly how much resource a viz took, how long it took Tableau to render the viz, and exactly the compute information of chip and graphics were involved. This would be one of the logs that Tableau are likely to ask for when making a report as this contains everything about the pc environment that Tableau could need without the user sending their pc to Tableau. |
| Flat file (txt, csv,Excel, Access, Google sheet etc) | Hyperd.txt | Contains everything related to the query used to build the visualisation, and includes all the activity surrounding how Tableau prepared the query, the connections made, where the query was sent, data pipes involved along with server worker information; and then, query execution time, numbers of CPU's, cores and workers involved in executing and compiling the query, and whether the query resulted in a success. If the query errored, the error information is also captured to this log. | |
| tabprotosrv.txt | On the other hand is much more about the data source meta combined with the server hardware environment.
No query information is captured here, nor is there any information related to hardware use in the query, though this log will capture more information surrounding errors and/or unexpected or unaccounted errors. | ||
| Database (SQL Server, Oracle, Teradata, Postgresdb et al) | Hyperd.txt | Is now capturing the meta information as regards the query output AS A PREPARATION FOR creating an extract; in this way, Hyperd is understanding the queries, the elapsed time, data source meta etc to be included with an extract if one is created, much like the execution plan cache that all servers keep on each successive run of the same query. Sure, this information is useful for error-tracing though its primary purpose is for query performance optimisation. | |
| tabprotosrv.txt (1) | On the other hand now comes as TWO files one created a split second after the other, so it is important when using the logs to determine your need and both identify and open the correct one. Typically, the first tabprotosrv file contains all the same information as is captured in the same file when working with Excel, that of data environment including query time, but also, all the table meta and errors encountered etc. | ||
| tabprotosrv.txt (2) | The second Tabprotosrv file contains the other side of what is captured to the Hyperd.txt when query flat file which is to say, this is the file needed to identify the queries issued by Tableau to the data-source, and plays the pivotal role in performance optimisation. | ||
So now we know where the logs are stored, and broadly the information they contain, lets take a look at using them.
Usage and Retention
Due to the logs' naming only being tied to the date and time in which the were created, retaining logs beyond your work serves very little purpose, especially as multiple workbooks will share and write to the same log leading to cross-referencing. As a result, when it comes to the time that you need to use the logs such as, for error tracing, or optimisation, you can just go ahead and clear-out the logs directory.
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