git_update/test/performance_tests

Introduction

Our objective is to find the least-consuming method in terms of memory and bandwidth resources. We are interested in cloning one specific state of the repository. We are not interested in its history or the possibility to change it from the server where it has been cloned. The tests rely on a repository created by test_repo_creation.sh. It measures memory and bandwidth usage for different git commande.

Tests

The script consists of twenty-nine tests (listed in the results below), based on three functions: generate_random_file, get_storage_used and get_bandwidth.

generate_random_file uses the bash command dd and /dev/random. get_storage_used uses the bash command du. get_bandwidth retrieves the output of Git commands and extracts the traffic displayed. This does not take submodule traffic into account.

The first five tests concern cloning. The following tests involve updating the repository using different commands, with three cases for each command: after adding a file, after deleting a file, after adding then deleting a file.

Help extract

NAME performance_tests.sh SYNOPSIS performance_tests.sh [-a] [-h] [-n number] OPTIONS -a executes all the tests. -n number executes test number. -c cleans. -h prints the help. DESCRIPTION This script allows you to measure memory and bandwidth usage. The first five test different cloning methods. Te following apply changes to the local remote before testing fetching and merging commands. TEST0: classic cloning TEST1: --single-branch cloning TEST2: --depth=1 --no-single-branch cloning TEST3: --depth=1 cloning TEST4: --depth=1 with reflog and gc cloning TEST5: sparse-checking 1M sample0 cloning _________________ TEST6: classic fetching+checking out after addition of a 1M file TEST7: classic fetching+checking out after removal of a 1M file TEST8: classic fetching+checking out after addition then removal of a 1M file

TEST9: --depth=1 fetching+checking out after addition of a 1M file
TEST10: --depth=1 fetching+checking out after removal of a 1M file
TEST11: --depth=1 fetching+checking out after addition then removal of 1M a file

TEST12: --depth=1 fetching+checking out with reflog annd gc after addition of a 1M file
TEST13: --depth=1 fetching+checking out with reflog annd gc after removal of a 1M file
TEST14: --depth=1 fetching+checking out with reflog annd gc after addition then removal of a 1M file

TEST15: --depth=1 fetching+ --reset=hard after addition of a 1M file
TEST16: --depth=1 fetching+ --reset=hard after removal of a 1M file
TEST17:  --depth=1 fetching+ --reset=hard after addition then removal of a 1M file

TEST18: --depth=1 fetching+ --reset=hard and reflog and gc after addition of a 1M file
TEST19: --depth=1 fetching+ --reset=hard and reflog and gc after removal of a 1M file
TEST20: --depth=1 fetching+ --reset=hard and reflog and gc after addition then removal of a 1M file

TEST21: --depth=1 fetching+checking out after addition of a 1M file in submodule
TEST22: --depth=1 fetching+checking out after removal of a 1M file in submodule
TEST23: --depth=1 fetching+checking out after addition then removal of a 1M file in submodule 

TEST24: --depth=1 fetching+merging -X theirs with reflog and gc after addition of a 1M file
TEST25: --depth=1 fetching+merging -X theirs with reflog and gc after removal of a 1M file
TEST26: --depth=1 fetching+merging -X theirs with reflog and gc after addition then removal of a 1M file

TEST27: --depth=1 fetching+merging -s ours with reflog and gc after addition of a 1M file
TEST28: --depth=1 fetching+merging -s ours with reflog and gc after removal of a 1M file
TEST29: --depth=1 fetching+merging -s ours with reflog and gc after addition then removal of a 1M file"

To go further

To learn more about the process of testing different git methods conducted, please refer to doc/developement_explanations.md.