Cache Server and Tableau Prep Flow Authoring Fail to Start

Published: 28 Sep 2021
Last Modified Date: 29 Nov 2023


Tableau Server is in a degraded state or fails to initialize with the following services in an error state: Cache Server and Tableau Prep Flow Authoring

The log in "<data directory>\tabsvc\logs\cacheserver\redis_0.log" will show messages similar to the following:
[21236] 08 Sep 13:18:29.764 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
[21236] 08 Sep 13:18:29.764 # Redis version=6.0.11, bits=64, commit=0, modified=0, pid=21236, just started
[21236] 08 Sep 13:18:29.764 # Configuration loaded
[21236] 08 Sep 13:18:29.770 # Could not create server TCP listening socket *:8871: listen: Unknown error


  • Tableau Server 2021.2 or later
  • Tableau Server 2021.1.5 or later
  • Tableau Server 2020.4.8 or later
  • Windows


Option 1

Upgrade to Tableau Server 2021.4.4, 2021.3.8, 2021.2.9, 2021.1.12, or 2020.4.15.

Option 2

For the environment using VMware, removing the vnetflt.sys network inspection driver from the VM resolves the issue. See

If the above does not apply or does not resolve the issue, the following steps can be used as a workaround:
  1. On each node experiencing the issue, open the file "<install directory>\packages\templates.<version>\redis.conf.ftl" in a text editor.
  2. Add the following as a new line at the end of the file, then save it: bind
  3. Make a minor configuration change via tsm, such as:
    1. tsm configuration get -k gateway.timeout
    2. tsm configuration set -k gateway.timeout -v <previous value + 1>
    3. tsm pending-changes apply
For new installations, edit the redis.conf.ftl file after installing but before initializing Tableau Server.


This is a known issue that is fixed in more recent version of Tableau Server. 
In some environments, newer versions of Cache Server are unable to bind to IPv6, causing the process to fail to start. The Flow Authoring service then fails to start due to its dependency on Cache Server.

Additional Information

Tableau Server 2020.4 and earlier use .templ files as templates, Tableau Server 2021.1 and newer use .ftl files as templates. 
If a customer uses Tableau Server 2020.4 and earlier, please edit redis.conf.templ file.
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