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DRIVERS-3427 Phase 1 rollout: configurable retries, retargeting knob #1917

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DRIVERS-3427 Phase 1 rollout: configurable retries, retargeting knob #1917

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DRIVERS-3427 Phase 1 rollout: configurable retries, retargeting knob,…
Jibola Mar 24, 2026
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Jibola Mar 24, 2026
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Change default MAX_RETRIES value and configuration note
Jibola Mar 25, 2026
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Update MAX_RETRIES option to include 'maxRetries'
Jibola Mar 25, 2026
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Jibola Mar 25, 2026
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11 changes: 6 additions & 5 deletions source/client-backpressure/client-backpressure.md
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Expand Up @@ -122,7 +122,7 @@ rules:
2. A retry attempt will only be permitted if:
1. The error is a retryable overload error.
2. We have not reached `MAX_RETRIES`.
- The value of `MAX_RETRIES` is 5 and non-configurable.
- The default value of `MAX_RETRIES` is 2. Drivers MUST expose this as a configurable option `maxRetries`.
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@NoahStapp NoahStapp Mar 30, 2026

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Is maxRetries both a MongoClient constructor kwarg and a URI option? If we allow setting it in the URI, we need to update the URI spec.

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@NoahStapp NoahStapp Mar 30, 2026

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maxRetries is also supposed to be maxAdaptiveRetries.

- This intentionally changes the behavior of CSOT which otherwise would retry an unlimited number of times within
Comment on lines 124 to 126
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Copilot AI Mar 26, 2026

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The PR description mentions a new maxAdaptiveRetries driver option, but this spec text requires drivers to expose MAX_RETRIES as maxRetries. Please align the option name between the PR description and the spec (and ensure the chosen name is used consistently throughout the spec).

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the timeout to avoid retry storms.
3. (CSOT-only): There is still time for a retry attempt according to the
Expand All @@ -142,9 +142,10 @@ rules:
- `MAX_BACKOFF` is 10000ms.
- This results in delays of 100ms, 200ms, 400ms, 800ms, and 1600ms before accounting for jitter.
4. If the request is eligible for retry (as outlined in step 2 above and step 4 in the
[adaptive retry requirements](client-backpressure.md#adaptive-retry-requirements) below), the client MUST add the
previously used server's address to the list of deprioritized server addresses for
[server selection](../server-selection/server-selection.md).
[adaptive retry requirements](client-backpressure.md#adaptive-retry-requirements) below) and
`enableOverloadRetargeting` is enabled, the client MUST add the previously used server's address to the list of
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@NoahStapp NoahStapp Mar 30, 2026

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Same question here.

deprioritized server addresses for [server selection](../server-selection/server-selection.md). Drivers MUST expose
this as a configurable boolean option named `enableOverloadRetargeting` defaulting to `false`.
Comment on lines +147 to +148
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Copilot AI Mar 26, 2026

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Rule 4 now gates adding the previously-used server to the deprioritized list behind enableOverloadRetargeting, but the pseudocode later in this document still unconditionally appends the server address to deprioritized_servers. Please update the pseudocode/algorithm description to match the new conditional behavior so the spec is internally consistent.

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deprioritized server addresses for [server selection](../server-selection/server-selection.md). Drivers MUST expose
this as a configurable boolean option named `enableOverloadRetargeting` defaulting to `false`.
deprioritized server addresses for [server selection](../server-selection/server-selection.md). If
`enableOverloadRetargeting` is disabled, the client MUST NOT add the previously used server's address to this list.
Drivers MUST expose this as a configurable boolean option named `enableOverloadRetargeting` defaulting to `false`.

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5. If the request is eligible for retry (as outlined in step 2 above and step 4 in the
[adaptive retry requirements](client-backpressure.md#adaptive-retry-requirements) below) and is a retryable write:
1. If the command is a part of a transaction, the instructions for command modification on retry for commands in
Expand Down Expand Up @@ -199,7 +200,7 @@ BASE_BACKOFF = 0.1 # 100ms
MAX_BACKOFF = 10 # 10000ms

RETRY_TOKEN_RETURN_RATE = 0.1
MAX_RETRIES = 5
MAX_RETRIES = 2

def execute_command_retryable(command, ...):
deprioritized_servers = []
Expand Down
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