Maximise Inventory File Upload Performance

You can generally get the best overall upload processing performance by following these guidelines:

• Avoid submitting a lot of files with only a few records in each file. When possible, combine the data into fewer, larger files.
• Include only the products you are updating, not your entire inventory.
• Upload one file of the same type no more than every 20 minutes.
• Keep file sizes below 10 MB.

Processing by file type

To help ensure that updates occur in the order files are uploaded, we generally separate files by type, and then process them sequentially, except as noted below.

For tab-delimited text files, each seller's files are separated into the following types and processed one at a time within each type, except as noted:

• Listing updates, including product, price, and inventory updates
• Shipping confirmations
• Order refunds (more than one can be processed at a time)

For XML files, each seller's files are separated into the following types and processed one at a time within each type, except as noted:

• Product updates
• Price updates
• Inventory updates
• Post-Order acknowledgments
• Order refunds (more than one can be processed at a time)

If you submit multiple files of the same type (except refunds), they will generally be processed in succession. However, files of different types can process at the same time. For example, if you submit 10 listing files and then submit one shipping confirmation file, the shipping confirmation file may begin processing before the listing files are done processing.

File processing steps

Here are the basic file processing steps for every file you upload:

1. The file waits its turn in the queue if you have submitted one or more previous files of the same type (except refunds), and they are not all done processing.
2. After all previous files have completed processing, the new file is set up to start processing.
3. The file is processed and the file's updates are made.
4. Any file errors are recorded in the file's processing report.

One key to maximising the overall performance of your files is reducing the number of times steps 1, 2, and 4 happen for your files as a whole. Each step adds to processing time, and step 2 can take as long for a small file as it does for a larger file.