What is the size limit of a cosmosdb item?
The maximum size of a document today is 2MB.
https://docs.microsoft.com/en-us/azure/cosmos-db/documentdb-resources#documents
So this is one of those things that always annoys me about documentation.
Sure it's 2MB, but by who's measuring stick.
TLDR: Between 2,090,014 and 2,100,014 when Encoding.UTF8.GetByteCount(doc) or Encoding.ASCII.GetByteCount(doc)
To get there I set up the following code:
for (int i = 10; i < 10000; i++)
{
var docItem = new TestItem(new string('A', i * 10000));
string doc = JsonConvert.SerializeObject(docItem);
log.LogInformation(" ");
log.LogInformation(" -------------------------------------------------------------------------------------------------------------------------------------");
log.LogInformation($" ------------------------------------------------- Doc Size = {i*10000 } --------------------------------------------------");
log.LogInformation(" -------------------------------------------------------------------------------------------------------------------------------------");
log.LogWarning($"UTF7 - {Encoding.UTF7.GetByteCount(doc)}");
log.LogWarning($"UTF8 - {Encoding.UTF8.GetByteCount(doc)}");
log.LogWarning($"UTF32 - {Encoding.UTF32.GetByteCount(doc)}");
log.LogWarning($"Unicode - {Encoding.Unicode.GetByteCount(doc)}");
log.LogWarning($"Ascii - {Encoding.ASCII.GetByteCount(doc)}");
log.LogInformation(" -------------------------------------------------------------------------------------------------------------------------------------");
log.LogWarning($"UTF7 - {ASCIIEncoding.UTF7.GetByteCount(doc)}");
log.LogWarning($"UTF8 - {ASCIIEncoding.UTF8.GetByteCount(doc)}");
log.LogWarning($"UTF32 - {ASCIIEncoding.UTF32.GetByteCount(doc)}");
log.LogWarning($"Unicode - {ASCIIEncoding.Unicode.GetByteCount(doc)}");
log.LogWarning($"Ascii - {ASCIIEncoding.ASCII.GetByteCount(doc)}");
try
{
await cosmosStore.CreateDocumentAsync(docItem);
}
catch (Exception e)
{
log.LogWarning(e.Message + "Caught");
}
}
And here's where it broke:
Update: increasing the max size to 16 MB is now possible. https://devblogs.microsoft.com/cosmosdb/larger-document-sizes-unique-index-improvements-expr-support-in-azure-cosmos-db-api-for-mongodb/