From 0e5925fff6d9b3147de4967e1963b4c785d0055f Mon Sep 17 00:00:00 2001 From: Alex Auvolat Date: Fri, 22 Sep 2023 16:09:17 +0200 Subject: [PATCH] layout doc: reformulate --- doc/book/operations/layout.md | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/doc/book/operations/layout.md b/doc/book/operations/layout.md index 0eb0e215..ece17ddb 100644 --- a/doc/book/operations/layout.md +++ b/doc/book/operations/layout.md @@ -94,12 +94,13 @@ follow the following recommendations: ## Understanding unexpected layout calculations When adding, removing or modifying nodes in a cluster layout, sometimes -unexpected assigntations of partitions to node can occure. These assignations +unexpected assigntations of partitions to node can occur. These assignations are in fact normal and logical, given the objectives of the algorihtm. Indeed, **the layout algorithm prioritizes moving less data between nodes over the fact -of achieving equal distribution of load**. This section presents two examples -and illustrates how one can control Garage's behavior to obtain the desired -results. +of achieving equal distribution of load. It also tries to use all links between +pairs of nodes in equal proportions when moving data.** This section presents +two examples and illustrates how one can control Garage's behavior to obtain +the desired results. ### Example 1 @@ -266,8 +267,8 @@ This explains why node3 ends with 75% utilization (100% from before minus 25% that is moved to node1), and node4 ends with 25% (50% from before minus 25% that is moved to node1). -This illustrates another principle of the layout computation: **if there is a -choice in moving data out of some nodes, then all links between pairs of nodes -are used in equal proportions** (this is approximately true, there is +This illustrates the second principle of the layout computation: **if there is +a choice in moving data out of some nodes, then all links between pairs of +nodes are used in equal proportions** (this is approximately true, there is randomness in the algorihtm to achieve this so there might be some small fluctuations, as we see above).