Skip to content

Clarify need for exchange manager configuration #18029

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
mosabua merged 1 commit into from
Jun 27, 2023
Merged

Clarify need for exchange manager configuration #18029

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
14 changes: 7 additions & 7 deletions docs/src/main/sphinx/admin/fault-tolerant-execution.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -98,8 +98,7 @@ QUERY
A ``QUERY`` retry policy instructs Trino to automatically retry a query in the
event of an error occuring on a worker node. A ``QUERY`` retry policy is
recommended when the majority of the Trino cluster's workload consists of many
small queries, or if an :ref:`exchange manager <fte-exchange-manager>` is not
configured.
small queries.
Comment thread
mosabua marked this conversation as resolved.
Outdated

By default Trino does not implement fault tolerance for queries whose result set
exceeds 32MB in size, such as :doc:`/sql/select` statements that return a very
Expand All @@ -116,11 +115,12 @@ therefore allows for storage of spilled data beyond the in-memory buffer size.
TASK
^^^^

A ``TASK`` retry policy instructs Trino to retry individual query
:ref:`tasks <trino-concept-task>` in the event of failure. This policy is
recommended when executing large batch queries, as the cluster can more
efficiently retry smaller tasks within the query rather than retry the whole
query.
A ``TASK`` retry policy instructs Trino to retry individual query :ref:`tasks
<trino-concept-task>` in the event of failure. You must configure an
:ref:`exchange manager <fte-exchange-manager>` to use the task retry policy.
This policy is recommended when executing large batch queries, as the cluster
can more efficiently retry smaller tasks within the query rather than retry the
whole query.

When a cluster is configured with a ``TASK`` retry policy, some relevant
configuration properties have their default values changed to follow best
Expand Down