# TransformerDebug In addition to any normal logging, the t-engines, t-router and t-client also use the `TransformerDebug` class to provide request based logging. The following is an example from Alfresco after the upload of a `docx` file. ~~~text 163 docx json AGM 2016 - Masters report.docx 14.8 KB -- metadataExtract -- TransformService 163 workspace://SpacesStore/0db3a665-328d-4437-85ed-56b753cf19c8 1563306426 163 docx json 14.8 KB -- metadataExtract -- PoiMetadataExtractor 163 cm:title= 163 cm:author=James Dobinson 163 Finished in 664 ms ... 164 docx png AGM 2016 - Masters report.docx 14.8 KB -- doclib -- TransformService 164 workspace://SpacesStore/0db3a665-328d-4437-85ed-56b753cf19c8 1563306426 164 docx png 14.8 KB -- doclib -- officeToImageViaPdf 164.1 docx pdf libreoffice 164.2 pdf png pdfToImageViaPng 164.2.1 pdf png pdfrenderer 164.2.2 png png imagemagick 164.2.2 endPage="0" 164.2.2 resizeHeight="100" 164.2.2 thumbnail="true" 164.2.2 startPage="0" 164.2.2 resizeWidth="100" 164.2.2 autoOrient="true" 164.2.2 allowEnlargement="false" 164.2.2 maintainAspectRatio="true" 164 Finished in 725 ms ~~~ This log happens to be from the t-client, but similar log lines exist in the t-router and individual t-engines. All lines start with a reference, which starts with the client’s request number (`163`, `164` if known) and then a nested pipeline or failover structure. The first request extracts metadata and the second creates a thumbnail rendition (called `doclib`). The second request is handled by a pipeline called `officeToImageViaPdf` which uses `libreoffice` to transform to `pdf` and then another pipeline to convert to `png`. The last step (`164.2.2`) in the process resizes the `png` using a number of transform options. If requested, log information is passed back in the TransformReply's clientData.