5 exercises on SDK deprecation notices and breaking-change changelogs. Learn to read announcements precisely, distinguish deprecated from removed, and identify migration steps.
Reading announcements and changelogs effectively
Deprecated vs. removed — deprecated = marked for future removal; removed = gone now, causes an error
Breaking vs. improvement — breaking changes require code action; improvements are free gains
Dates matter — support-end date and removal-version date are different deadlines
Title: Deprecating Python 2 Support in Our SDK — Action Required by 31 December 2024
We are announcing the deprecation of Python 2 support in the Acme SDK, effective
immediately, with full removal scheduled for version 4.0.0 (targeted Q1 2025).
What this means for you:
- SDK versions 3.x will continue to receive security patches until 31 December 2024.
- SDK version 4.0.0 will NOT install on Python 2 environments. Attempting to install
it will raise a hard error at the pip install step.
- No new features will be backported to 3.x.
Why we are making this change:
Python 2 reached end-of-life on 1 January 2020. Maintaining a dual-compatible
codebase requires extensive workarounds (six, future, manual __future__ imports)
that slow development velocity and introduce subtle bugs. Type annotations, dataclasses,
f-strings, and walrus operators — all Python 3-only — are now essential to writing
maintainable code.
Migration guide:
1. Upgrade your runtime to Python 3.10 or later.
2. Run: pip install acme-sdk --upgrade
3. If you use any deprecated Python 2 syntax in your integration code, run:
python -m 2to3 -w your_integration/
4. Review our full migration checklist at docs.acme.io/sdk/migrate-py3
If you have a contractual requirement to stay on Python 2, contact support@acme.io
before 31 October 2024 to discuss extended support options.
After 31 December 2024, what will happen to users who are still running SDK version 3.x?
SDK 3.x stops receiving security patches but keeps working.
The announcement says: "SDK versions 3.x will continue to receive security patches until 31 December 2024." This implies that after that date, patches stop — but the existing installed version continues to function. It does not say 3.x will break or be disabled.
Reading deprecation notices precisely:
Deprecation announcements have two distinct dates: when support ends and when removal happens (in version 4.0.0).
"No new features backported" and "no patches after date X" are support changes, not removal.
The hard break comes only when users upgrade to v4.0.0 — existing installs are not touched.
Key vocabulary:
end-of-life — no further patches or updates, but still usable.
deprecated — marked for removal in a future version; still present now.
Title: Deprecating Python 2 Support in Our SDK — Action Required by 31 December 2024
We are announcing the deprecation of Python 2 support in the Acme SDK, effective
immediately, with full removal scheduled for version 4.0.0 (targeted Q1 2025).
What this means for you:
- SDK versions 3.x will continue to receive security patches until 31 December 2024.
- SDK version 4.0.0 will NOT install on Python 2 environments. Attempting to install
it will raise a hard error at the pip install step.
- No new features will be backported to 3.x.
Why we are making this change:
Python 2 reached end-of-life on 1 January 2020. Maintaining a dual-compatible
codebase requires extensive workarounds (six, future, manual __future__ imports)
that slow development velocity and introduce subtle bugs. Type annotations, dataclasses,
f-strings, and walrus operators — all Python 3-only — are now essential to writing
maintainable code.
Migration guide:
1. Upgrade your runtime to Python 3.10 or later.
2. Run: pip install acme-sdk --upgrade
3. If you use any deprecated Python 2 syntax in your integration code, run:
python -m 2to3 -w your_integration/
4. Review our full migration checklist at docs.acme.io/sdk/migrate-py3
If you have a contractual requirement to stay on Python 2, contact support@acme.io
before 31 October 2024 to discuss extended support options.
The announcement says "maintaining a dual-compatible codebase requires extensive workarounds." Which of the following is given in the passage as an example of such a workaround?
The six library is cited as a compatibility workaround.
The announcement lists these as examples of workarounds: "six, future, manual __future__ imports." These are real tools developers used to write code that ran on both Python 2 and Python 3 simultaneously.
Why the other options are wrong:
Options A and B (f-strings and type annotations) are listed as Python 3-only features that make modern code maintainable — they are reasons to drop Python 2, not compatibility workarounds.
Option D (2to3) is in the migration guide, not in the "workarounds" list.
Reading strategy — section awareness: Announcements are typically divided into: What this means for you, Why we are making this change, and Migration guide. Questions often test whether you can locate information in the correct section, not just whether you saw the words somewhere in the document.
3 / 5
Passage: acme-auth v5.0.0 Changelog
Title: Changelog — acme-auth v5.0.0 (Breaking Changes)
Released: 2024-08-15
BREAKING CHANGES — read before upgrading:
1. JWT algorithm changed from HS256 to RS256
HS256 used a shared symmetric key. RS256 uses an asymmetric key pair
(private key for signing, public key for verification). You must:
a) Generate a new RSA-2048 key pair (see docs/keygen.md).
b) Update your ACME_AUTH_PRIVATE_KEY and ACME_AUTH_PUBLIC_KEY env vars.
c) Rotate all existing tokens — HS256 tokens are rejected from this version.
2. Session duration reduced from 24 hours to 8 hours (configurable)
The default session lifetime is now 8 hours to align with security best
practices. To restore the previous behaviour:
ACME_SESSION_TTL=86400 # seconds
3. The /api/v1/auth/refresh endpoint removed
Use /api/v2/auth/refresh. The v1 endpoint returns 410 Gone.
IMPROVEMENTS:
- 40% reduction in token verification latency (RS256 public-key operations
are cached per process lifecycle).
- New audit log: every token issuance and refresh is now written to
audit.log in structured JSON format.
A team upgrades to acme-auth v5.0.0 without reading the changelog. Their application calls /api/v1/auth/refresh. What response will it receive?
410 Gone — the v1 endpoint is permanently removed.
The changelog states explicitly: "The /api/v1/auth/refresh endpoint removed. Use /api/v2/auth/refresh. The v1 endpoint returns 410 Gone."
HTTP 410 vs. 301 vs. 404:
301 Moved Permanently — the resource has moved to a new URL; the browser/client should follow the redirect automatically.
404 Not Found — the resource does not exist (may be temporary or permanent).
410 Gone — the resource existed but has been permanently removed. Unlike 404, it signals to clients and search engines that the URL will never return.
APIs use 410 (not 301) for removed endpoints to force clients to update their code rather than silently following a redirect. A 301 redirect would mask the breaking change.
4 / 5
Passage: acme-auth v5.0.0 Changelog
Title: Changelog — acme-auth v5.0.0 (Breaking Changes)
Released: 2024-08-15
BREAKING CHANGES — read before upgrading:
1. JWT algorithm changed from HS256 to RS256
HS256 used a shared symmetric key. RS256 uses an asymmetric key pair
(private key for signing, public key for verification). You must:
a) Generate a new RSA-2048 key pair (see docs/keygen.md).
b) Update your ACME_AUTH_PRIVATE_KEY and ACME_AUTH_PUBLIC_KEY env vars.
c) Rotate all existing tokens — HS256 tokens are rejected from this version.
2. Session duration reduced from 24 hours to 8 hours (configurable)
The default session lifetime is now 8 hours to align with security best
practices. To restore the previous behaviour:
ACME_SESSION_TTL=86400 # seconds
3. The /api/v1/auth/refresh endpoint removed
Use /api/v2/auth/refresh. The v1 endpoint returns 410 Gone.
IMPROVEMENTS:
- 40% reduction in token verification latency (RS256 public-key operations
are cached per process lifecycle).
- New audit log: every token issuance and refresh is now written to
audit.log in structured JSON format.
What does the changelog say about the performance impact of switching from HS256 to RS256?
40% reduction in token verification latency.
The changelog states under IMPROVEMENTS: "40% reduction in token verification latency (RS256 public-key operations are cached per process lifecycle)."
Why this is counter-intuitive: Asymmetric cryptography (RS256) involves more computation per operation than symmetric cryptography (HS256). However, because verification only uses the public key — and the public key can be cached in memory once per process start — repeated verifications are very fast. The initial overhead is amortised over millions of token verifications.
Reading changelogs strategically:
Breaking changes — require code changes before upgrading.
Improvements — desirable side effects; no code change needed.
Bug fixes — problems that were fixed.
Always read BREAKING CHANGES first, then judge whether the IMPROVEMENTS justify the migration cost.
5 / 5
Passage: acme-auth v5.0.0 Changelog
Title: Changelog — acme-auth v5.0.0 (Breaking Changes)
Released: 2024-08-15
BREAKING CHANGES — read before upgrading:
1. JWT algorithm changed from HS256 to RS256
HS256 used a shared symmetric key. RS256 uses an asymmetric key pair
(private key for signing, public key for verification). You must:
a) Generate a new RSA-2048 key pair (see docs/keygen.md).
b) Update your ACME_AUTH_PRIVATE_KEY and ACME_AUTH_PUBLIC_KEY env vars.
c) Rotate all existing tokens — HS256 tokens are rejected from this version.
2. Session duration reduced from 24 hours to 8 hours (configurable)
The default session lifetime is now 8 hours to align with security best
practices. To restore the previous behaviour:
ACME_SESSION_TTL=86400 # seconds
3. The /api/v1/auth/refresh endpoint removed
Use /api/v2/auth/refresh. The v1 endpoint returns 410 Gone.
IMPROVEMENTS:
- 40% reduction in token verification latency (RS256 public-key operations
are cached per process lifecycle).
- New audit log: every token issuance and refresh is now written to
audit.log in structured JSON format.
A developer wants to keep the session duration at 24 hours after upgrading to v5.0.0. What does the changelog instruct them to do?
Set ACME_SESSION_TTL=86400.
The changelog states: "The default session lifetime is now 8 hours... To restore the previous behaviour: ACME_SESSION_TTL=86400 # seconds"
Why 86400? 86,400 is the number of seconds in 24 hours (60 seconds × 60 minutes × 24 hours = 86,400). Setting the TTL in seconds is the standard approach because it is unambiguous — unlike "hours" or "minutes," "seconds" requires no interpretation.
Option D trap: Setting ACME_SESSION_TTL=24 might look correct if you read "24 hours" without noticing the comment # seconds. This would give a 24-second session — a very common misconfiguration when a value is in seconds but the developer assumed it was in hours.
Changelog reading tip: Inline code comments (# seconds, # milliseconds) in configuration examples are not decorative — they define the unit. Always check the unit before copying a config value.