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Real-time Virtual Appliance

High-Level Summary

This release provides internal bug and security fixes. It is recommended that customers on previous releases upgrade to this version.

Important Notices

Currently, Speechmatics supports 2 python libraries for use with our Real-time products. smwebsocket-py is recommended for use for the Real-time Virtual Appliance only, and speechmatics-python is recommended for use in both our Real-time Container and our Real-time Virtual Appliance. In a future release we will exclusively support speechmatics-python as our preferred Python library. We recommend you familiarise yourself with this library and use wherever possible. Please contact if you require access to this library.

If you are importing an appliance using VMWare, please note that the hardware_version of the appliance has been updated from 9 to 11. This is to automatically take advantages of performance optimisation using Advanced Vector Extensions 2 (AVX2). This should have no effect on the appliance assuming you are on a version of VMWare ESXi supported by Speechmatics (versions 6.5 onwards). If you are importing an appliance through VirtualBox, and AVX2 is not automatically enabled, you can also take advantage of the the performance benefits from AVX 2 following these guidelines.

It is now necessary to run the appliance on processors that support AVX2 in order to take advantage of latest performance optimisations.

What's New

  • Internal bug and security fixes
  • Customers who use the Glances API output should be aware that as part of critical bug fixes the API version supported is version 3 due to critical bug fixes - further information can be found here. Interaction with Glances via the Management API has changed to reflect the Glances API update - please see the monitoring and alerting section of the Installation Guide for an example.

Known Limitations

The following are known issues in this release:

Issue IDSummaryDetailed Description and Possible Workarounds
REQ-1409Proteus HCL with <unk> causes out of memory errorA custom dictionary list that contains the word '' causes the worker to crash.
REQ-7549Memory leak affecting gRPCThere is a small memory leak in the gRPC Python server
REQ-10160Advanced punctuation for Spanish (es) does not contain inverted marks.Inverted marks [ ¿ ¡ ] are not currently available for Spanish advanced punctuation.
REQ-10627Double full stops when acronym is at the end of the sentenceIf there is an acronym at the end of the sentence, then a double full stop will be output, for example: "team G.B.."
REQ-11792Speaker change token positioning is incorrectWe are aware of a consistent mis-placing of the speaker change token after the first word of the new speakers' sentence rather than before it.
REQ-12202High memory usage when using custom dictionaryIt has been observed that when using custom dictionary an additional 800-1700MB of memory is required (depending on the size of the wordlist used).
REQ-16256Heavy usage of RAM when swapping between 8kHz and 16kHz inputWhere multiple persistent workers are configured with Custom Dictionary that swap between 8kHz and 16kHz input, this can cause a memory leak that causes the container to crash. If this starts to impact services it is recommended to restart all the services with the management API or drop the worker count to 1 and then increase it again

Supported Platforms

Virtual Appliance image (OVA) for installation on:

  • VMware ESXi 6.5+ or VMware Workstation Player.
  • VirtualBox 5.2+
  • Amazon EC2

See the Installation and Admin Guide for details on the minimum specifications for the VM. The maximum number of concurrent jobs (maxworkers) that you can run on a single appliance is 30.

Form Factors

There are five variants of the Real-time Virtual Appliance.

VariantImage SizeMax. Disk SpaceLanguages
mini14GB40GBen, de, es
midi26GB60GBen, de, es, fr, ko, ja, nl, pt
maxi43GB80GBen, de, es, fr, ko, ja, nl, pt, it, da, pl, ca, hi, ru, sv
plus45GB80GBen, cmn, no, ar, bg, cs, el, fi, hu, hr, lt, lv, ro, sk, sl, tr, ms

Upgrade Path

Remove the license from your old appliance (see the Admin Guide), then re-import the new OVA and configure networking as per the Installation and Admin guide. You will need to re-apply the license code you have once the OVA has imported.


Upload the OVA to VMWare ESX, VMWare Workstation Player, or VirtualBox. See the Installation and Admin Guide for more information.