PYTHON-5808 Drop support for MongoDB 4.2 by blink1073 · Pull Request #2892 · mongodb/mongo-python-driver

blink1073 · 2026-06-24T21:59:22Z

Changes in this PR

Drops MongoDB 4.2 support, making MongoDB 4.4 (wire version 9) the new minimum. Removes dead code paths that only applied to pre-4.2 servers.

Test Plan

Standard test suite.

Checklist

Checklist for Author

Did you update the changelog (if necessary)?
Is there test coverage?
Is any followup work tracked in a JIRA ticket? If so, add link(s).

Checklist for Reviewer

Does the title of the PR reference a JIRA Ticket?
Do you fully understand the implementation? (Would you be comfortable explaining how this code works to someone else?)
Is all relevant documentation (README or docstring) updated?

Bump minimum supported server version to MongoDB 4.4 (wire version 9). Remove dead code paths that only applied to wire version < 8 servers, including the legacy OP_GET_MORE protocol, the use_command dispatch mechanism, and the from_command response field.

codecov-commenter · 2026-06-24T22:36:46Z

Codecov Report

❌ Patch coverage is 95.83333% with 2 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
pymongo/asynchronous/aggregation.py	50.00%	0 Missing and 1 partial ⚠️
pymongo/synchronous/aggregation.py	50.00%	0 Missing and 1 partial ⚠️

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Update post-42-*.json SDAM error fixtures and test_wire_version to use wire version 9 (MongoDB 4.4), which is now the minimum supported version.

This reverts commit b2b6c5b.

Skip SDAM error spec tests whose mock servers report wire versions below the new minimum (9 / MongoDB 4.4), and update the test_wire_version assertion to use MIN_SUPPORTED_WIRE_VERSION.

Update mock servers in mockupdb tests to use MIN_SUPPORTED_WIRE_VERSION instead of the hardcoded wire version 8 (MongoDB 4.2).

Fix shlex-splitting bug in coverage command that broke multi-word marker expressions (e.g. 'not default_async and default') when GREEN_FRAMEWORK is set, by building subprocess args as a list instead of a shell string. Switch enterprise auth setup to use SASL_HOST_BUILD and PRINCIPAL_BUILD secrets so GSSAPI and SASL tests connect to a MongoDB 4.4+ server instead of the legacy 4.2 LDAP test server.

The KEYTAB_BASE64 keytab only contains entries for the old PRINCIPAL (ldaptest.10gen.cc). Switch to KEYTAB_BASE64_BUILD which matches PRINCIPAL_BUILD (ldaptest.build.10gen.cc).

blink1073 · 2026-06-25T14:19:49Z

This is currently blocked on getting appropriate credentials for the new 4.4 enterprise test server

Use the original KEYTAB_BASE64 secret for kinit.

Point kinit at ldaptest.build.10gen.cc (the MongoDB 4.4+ LDAP server) by writing a krb5.conf with the appropriate realm configuration instead of using an empty file.

…THON-5808 # Conflicts: # .evergreen/generated_configs/tasks.yml # .evergreen/scripts/generate_config_utils.py # doc/changelog.rst # pymongo/asynchronous/mongo_client.py # pymongo/asynchronous/server.py # pymongo/message.py # pymongo/synchronous/mongo_client.py # pymongo/synchronous/server.py

Upstream removed the use_cmd parameter from _Query.get_message(). Update the call site in cursor_base.py to match the new signature.

…tructors

…stro

Copilot

Pull request overview

Raises PyMongo’s minimum supported MongoDB version to 4.4 and removes obsolete compatibility paths.

Changes:

Sets minimum wire version to 9 and simplifies runtime logic.
Removes obsolete version-gated tests and regenerates CI configurations.
Updates compatibility documentation and adds unrelated CI bootstrap changes.

Reviewed changes

Copilot reviewed 80 out of 80 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
`README.md`	Updates supported server versions.
`doc/changelog.rst`	Records dropping MongoDB 4.2.
`pymongo/common.py`	Raises minimum server and wire versions.
`pymongo/message.py`	Removes legacy getMore protocol handling.
`pymongo/operations.py`	Removes obsolete 4.2 requirements.
`pymongo/response.py`	Removes legacy response-origin state.
`pymongo/encryption_options.py`	Updates encryption requirements.
`pymongo/asynchronous/aggregation.py`	Always applies supported read concern.
`pymongo/asynchronous/auth.py`	Removes legacy authentication branching.
`pymongo/asynchronous/auth_aws.py`	Removes redundant version validation.
`pymongo/asynchronous/bulk.py`	Removes obsolete hint compatibility tracking.
`pymongo/asynchronous/change_stream.py`	Uses server resumability labels exclusively.
`pymongo/asynchronous/collection.py`	Removes pre-4.4 option checks.
`pymongo/asynchronous/cursor.py`	Updates min/max hint documentation.
`pymongo/asynchronous/cursor_base.py`	Removes legacy cursor response plumbing.
`pymongo/asynchronous/mongo_client.py`	Simplifies retryable-write labeling.
`pymongo/asynchronous/pool.py`	Updates handshake compatibility comment.
`pymongo/asynchronous/topology.py`	Removes obsolete pool-clearing behavior.
`pymongo/synchronous/aggregation.py`	Sync counterpart for read concern.
`pymongo/synchronous/auth.py`	Sync authentication simplification.
`pymongo/synchronous/auth_aws.py`	Sync AWS validation cleanup.
`pymongo/synchronous/bulk.py`	Sync hint compatibility cleanup.
`pymongo/synchronous/change_stream.py`	Sync resumability simplification.
`pymongo/synchronous/collection.py`	Sync option-check cleanup.
`pymongo/synchronous/cursor.py`	Sync hint documentation update.
`pymongo/synchronous/cursor_base.py`	Sync cursor plumbing cleanup.
`pymongo/synchronous/mongo_client.py`	Sync retryable-write simplification.
`pymongo/synchronous/pool.py`	Sync handshake comment update.
`pymongo/synchronous/topology.py`	Sync topology behavior cleanup.
`test/__init__.py`	Simplifies test capability detection.
`test/asynchronous/__init__.py`	Async test capability detection.
`test/test_bulk.py`	Removes obsolete version gates.
`test/test_change_stream.py`	Removes obsolete change-stream gates.
`test/test_collection.py`	Removes legacy index/exhaust cases.
`test/test_connections_survive_primary_stepdown_spec.py`	Removes version decorators.
`test/test_csot.py`	Removes pre-4.0 workaround.
`test/test_cursor.py`	Retains only MongoDB 4.4 behavior.
`test/test_custom_types.py`	Removes change-stream version gates.
`test/test_database.py`	Removes legacy aggregation branch.
`test/test_discovery_and_monitoring.py`	Skips unsupported-wire scenarios.
`test/test_encryption.py`	Removes obsolete encryption gate.
`test/test_examples.py`	Removes MongoDB 4.4 decorator.
`test/test_message.py`	Updates getMore command tests.
`test/test_monitoring.py`	Removes deprecated find scenarios.
`test/test_on_demand_csfle.py`	Removes obsolete CSFLE gates.
`test/test_read_concern.py`	Assumes supported `$out` behavior.
`test/test_retryable_reads.py`	Removes minimum-version decorators.
`test/test_retryable_writes.py`	Removes retry-label version gates.
`test/test_sdam_monitoring_spec.py`	Removes pre-4.4 SDAM test.
`test/test_topology.py`	Uses shared minimum wire version.
`test/test_transactions.py`	Removes legacy transaction branches.
`test/asynchronous/test_bulk.py`	Async bulk test cleanup.
`test/asynchronous/test_change_stream.py`	Async change-stream gate cleanup.
`test/asynchronous/test_collection.py`	Async index/exhaust cleanup.
`test/asynchronous/test_connections_survive_primary_stepdown_spec.py`	Async decorator cleanup.
`test/asynchronous/test_csot.py`	Async workaround removal.
`test/asynchronous/test_cursor.py`	Async MongoDB 4.4 behavior.
`test/asynchronous/test_custom_types.py`	Async custom-type gate cleanup.
`test/asynchronous/test_database.py`	Async aggregation branch cleanup.
`test/asynchronous/test_discovery_and_monitoring.py`	Async unsupported-wire skipping.
`test/asynchronous/test_encryption.py`	Async encryption gate cleanup.
`test/asynchronous/test_examples.py`	Async example decorator cleanup.
`test/asynchronous/test_monitoring.py`	Async deprecated find cleanup.
`test/asynchronous/test_on_demand_csfle.py`	Async CSFLE gate cleanup.
`test/asynchronous/test_read_concern.py`	Async `$out` behavior update.
`test/asynchronous/test_retryable_reads.py`	Async retryable-read gate cleanup.
`test/asynchronous/test_retryable_writes.py`	Async retry-label gate cleanup.
`test/asynchronous/test_sdam_monitoring_spec.py`	Async pre-4.4 SDAM removal.
`test/asynchronous/test_transactions.py`	Async transaction cleanup.
`test/mockupdb/test_cursor_namespace.py`	Uses current minimum wire version.
`test/mockupdb/test_op_msg.py`	Updates mock server wire version.
`test/mockupdb/test_standalone_shard.py`	Updates standalone mock wire version.
`.evergreen/scripts/generate_config.py`	Removes MongoDB 4.2 exclusions.
`.evergreen/scripts/generate_config_utils.py`	Removes 4.2 from version matrix.
`.evergreen/generated_configs/tasks.yml`	Regenerates task matrix.
`.evergreen/generated_configs/variants.yml`	Removes MongoDB 4.2 variant.
`.evergreen/scripts/install-dependencies.sh`	Adds Python bootstrap workaround.
`.evergreen/scripts/setup-dev-env.sh`	Reloads generated environment settings.
`.evergreen/scripts/setup-uv-python.sh`	Adds missing-toolchain fallback.
`.evergreen/scripts/setup_tests.py`	Exports an additional SASL variable.

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blink1073 · 2026-08-25T20:35:42Z

+# Some images (e.g. the DEVPROD-19149 Windows image) ship without a Python toolchain.
+# A python3 may still be on PATH there (the mingw one that comes with chocolatey) that
+# runs but cannot bootstrap pip, so probe for one that can actually create a virtual
+# environment. We probe python3 specifically because that is the name
+# drivers-evergreen-tools' find_python3 falls back to, and it only checks that the
+# interpreter runs - not that it can build the venv it then goes on to need.


This logic can be removed, it was needed for the temporary host. I plan to open a ticket to use ensure_uv from drivers-evergreen-tools directly instead of duplicating the uv/python discovery here.

blink1073 added 6 commits June 24, 2026 18:47

PYTHON-5808 Fix CI failures after dropping MongoDB 4.2 support

b2b6c5b

Update post-42-*.json SDAM error fixtures and test_wire_version to use wire version 9 (MongoDB 4.4), which is now the minimum supported version.

Revert "PYTHON-5808 Fix CI failures after dropping MongoDB 4.2 support"

c38d908

This reverts commit b2b6c5b.

PYTHON-5808 Fix CI failures after dropping MongoDB 4.2 support

f4122aa

Skip SDAM error spec tests whose mock servers report wire versions below the new minimum (9 / MongoDB 4.4), and update the test_wire_version assertion to use MIN_SUPPORTED_WIRE_VERSION.

PYTHON-5808 Fix mockupdb CI failures after dropping MongoDB 4.2 support

6a1bad4

Update mock servers in mockupdb tests to use MIN_SUPPORTED_WIRE_VERSION instead of the hardcoded wire version 8 (MongoDB 4.2).

PYTHON-5808 Use KEYTAB_BASE64_BUILD for enterprise auth kinit

2a8974e

The KEYTAB_BASE64 keytab only contains entries for the old PRINCIPAL (ldaptest.10gen.cc). Switch to KEYTAB_BASE64_BUILD which matches PRINCIPAL_BUILD (ldaptest.build.10gen.cc).

blink1073 and others added 20 commits July 1, 2026 16:40

PYTHON-5808 Revert KEYTAB_BASE64_BUILD change in setup_tests.py

fcb2f7a

Use the original KEYTAB_BASE64 secret for kinit.

PYTHON-5808 Configure krb5.conf to use BUILD LDAP realm

bfe0f43

Point kinit at ldaptest.build.10gen.cc (the MongoDB 4.4+ LDAP server) by writing a krb5.conf with the appropriate realm configuration instead of using an empty file.

PYTHON-5808 Use PRINCIPAL (not PRINCIPAL_BUILD) for kinit and GSSAPI

07bd003

try with all new secrets

a853188

fix krb conf

48505a4

fix conf

bda89fd

fix conf

ad6c63a

use the windows-2022-latest-small-DEVPROD-19149 host

355fb92

use the windows-2022-latest-small-DEVPROD-19149 host

4025aba

PYTHON-5808 Fix _Query.get_message() call after merge

a817f99

Upstream removed the use_cmd parameter from _Query.get_message(). Update the call site in cursor_base.py to match the new signature.

PYTHON-5808 Remove from_command arg from Response/PinnedResponse cons…

04f7e23

…tructors

PYTHON-5808 Fix auth-enterprise-win64 variant to use DEVPROD-19149 di…

b2e776d

…stro

PYTHON-5808 Install Python via uv on images without a toolchain

f879a70

PYTHON-5808 Probe for a venv-capable Python before using the one on PATH

9a5583b

PYTHON-5808 Shadow the broken mingw python3 with the uv-installed one

f9d6d23

PYTHON-5808 Remove the DEVPROD-19149 Windows host override

1197951

PYTHON-5808 Use the unsuffixed enterprise auth secrets

2371450

Second pass

c3fe231

Merge branch 'main' into PYTHON-5808

6098d4b

NoahStapp requested a balanced review from Copilot August 25, 2026 19:37

Copilot started reviewing on behalf of NoahStapp August 25, 2026 19:38 View session

Copilot AI reviewed Aug 25, 2026

View reviewed changes

Cleanup + remove DEVPROD-19149 workaround

3fbaf37

NoahStapp marked this pull request as ready for review August 26, 2026 13:51

NoahStapp requested a review from a team as a code owner August 26, 2026 13:51

NoahStapp requested a review from aclark4life August 26, 2026 13:51

This was referenced Aug 26, 2026

PYTHON-5428 - @flaky calls cleanup between attempts #3006

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PYTHON-3419 Use memoryview to avoid byte copies when decoding larger RawBSONDocuments #3003

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PYTHON-5808 Drop support for MongoDB 4.2 - #2892

PYTHON-5808 Drop support for MongoDB 4.2#2892
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blink1073 commented Jun 24, 2026

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