Median JIRA Resolution Latency
established514.6 days Sep 2026
Based on: CHAOSS: Issue Resolution Duration, CHAOSS: Change Request Closure Ratio (adjacent)
Code and contributor health metrics: sustainability, review capacity, and responsiveness — computed from Git, ASF JIRA and GitHub PR history.
Faint points mark a month flagged low-n or insufficient data —
its statistic (a rate, an HHI, a median) comes from too few underlying events to be
reliable on its own. Hover a point for its exact n and flag; the value itself is unchanged.
Responsiveness
CHAOSS practitioner guide
-
Time to First Response (JIRA)
3.2 h
Jun 2026 · n=6
-
Stale PR Rate
35.3%
Oct 2026 · n=17
-
Open PR backlog
15
Sep 2026 · n=15
-
Median JIRA Resolution Latency
514.6 days
Sep 2026 · n=7
Responsiveness
Median JIRA Resolution Latency (12m cohort)
established101.9 days Aug 2026
Based on: CHAOSS: Issue Resolution Duration
Stale JIRA Issue Rate
established84.2% Oct 2026
Based on: CHAOSS: Change Requests (adjacent), CHAOSS: Change Requests Declined (adjacent)
PR Merge Lead Time
proxy12.9 days Aug 2026
PR Time to Close
proxy12.9 days Aug 2026
Based on: CHAOSS: Change Requests (adjacent)
Time to First Response (JIRA)
established3.2 h Jun 2026 backfill pending
Based on: CHAOSS: Time to First Response, CHAOSS: Responsiveness practitioner guide
Stale PR Rate
established35.3% Oct 2026
Based on: CHAOSS: Change Requests (adjacent), CHAOSS: Change Requests Declined (adjacent)
Change Request Closure Ratio — GitHub PR
proxy0.600 Sep 2026
Based on: CHAOSS: Change Request Closure Ratio
Change Request Closure Ratio — JIRA Patch Submissions
established0.400 Jun 2026 backfill pending
Based on: CHAOSS: Change Request Closure Ratio
Time to First Response (GitHub issues)
establishedn/a
insufficient data
Based on: CHAOSS: Issue Response Time, CHAOSS: Time to First Response
Issue Closure Ratio — GitHub Issues
proxyn/a
insufficient data
Based on: CHAOSS: Issues Closed (adapted)
Reviewer Capacity
PR Time to First Review
proxy16.2 h Aug 2026
Based on: CHAOSS: Time to First Response (GitHub-only variant)
Review responsiveness
How quickly a patch submission gets its first visible review response, split by how many
prior submissions the same contributor has -- a first-time submitter, a 2nd-5th submission, or
a 6th+ submission. A "submission" is one JIRA issue that ever reached
Patch Available, together with any linked GitHub pull request. "First visible
response" is the earliest of a JIRA comment, a JIRA status change to
Review In Progress/Ready to Commit, or a GitHub PR review/comment,
from someone other than the submission's own author -- review that happened somewhere this
project doesn't track (a private message, an in-person conversation) is invisible to this
section, so "no visible response" means exactly that, not "no response at all."
Methodology and caveats. The submission's author is reconstructed from JIRA's assignee-change history, which is a best-effort proxy, not a confirmed identity. Shares for "response within 7/30 days" and "no visible response" only count submissions old enough to judge (right-censoring: a submission newer than 7, 30, or 365 days is left out of that share's count entirely, not counted as a miss). These figures are informational only, shown with their own sample size (n) for context. Full definitions: METRICS.md.
First-time submitters
| Year | Submissions | Median days to first response | ≤7d | ≤30d | No visible response | Committed ≤365d |
|---|---|---|---|---|---|---|
| 2019 | 4 | insufficient data | insufficient data | insufficient data | insufficient data | insufficient data |
| 2020 | 1 | insufficient data | insufficient data | insufficient data | insufficient data | insufficient data |
| 2021 | 2 | insufficient data | insufficient data | insufficient data | insufficient data | insufficient data |
| 2022 | 2 | insufficient data | insufficient data | insufficient data | insufficient data | insufficient data |
| 2023 | 4 | insufficient data | insufficient data | insufficient data | insufficient data | insufficient data |
| 2024 | 7 | 0.0 | 100% | 100% | 0% | 86% |
| 2025 | 10 | 1.8 | 90% | 100% | 0% | 100% |
2nd-5th submission
| Year | Submissions | Median days to first response | ≤7d | ≤30d | No visible response | Committed ≤365d |
|---|---|---|---|---|---|---|
| 2019 | 2 | insufficient data | insufficient data | insufficient data | insufficient data | insufficient data |
| 2020 | 5 | 0.1 | 100% | 100% | 0% | 100% |
| 2021 | 2 | insufficient data | insufficient data | insufficient data | insufficient data | insufficient data |
| 2022 | 8 | 2.6 | 75% | 88% | 0% | 100% |
| 2023 | 10 | 0.1 | 90% | 90% | 0% | 100% |
| 2024 | 12 | 1.1 | 83% | 92% | 0% | 75% |
| 2025 | 25 | 1.0 | 60% | 84% | 4% | 90% |
6th+ submission
| Year | Submissions | Median days to first response | ≤7d | ≤30d | No visible response | Committed ≤365d |
|---|---|---|---|---|---|---|
| 2019 | 0 | insufficient data | insufficient data | insufficient data | insufficient data | insufficient data |
| 2020 | 2 | insufficient data | insufficient data | insufficient data | insufficient data | insufficient data |
| 2021 | 0 | insufficient data | insufficient data | insufficient data | insufficient data | insufficient data |
| 2022 | 7 | 0.1 | 71% | 86% | 14% | 86% |
| 2023 | 26 | 3.5 | 62% | 100% | 0% | 100% |
| 2024 | 61 | 0.5 | 89% | 98% | 0% | 100% |
| 2025 | 77 | 0.6 | 86% | 95% | 1% | 97% |
Trailing 12-month response-within-30-days share, by tier
Source of first response (2025 and later tiers combined)
| Source | Count | Share |
|---|---|---|
| GitHub PR comment | 62 | 56% |
| GitHub review | 24 | 22% |
| JIRA comment | 17 | 15% |
| JIRA status change | 7 | 6% |
Open PR backlog
The open apache/cassandra PR backlog by age and by linked-JIRA-ticket state, reconstructed monthly. Scoped to apache/cassandra: other configured repos use their own issue tracker or none, so ticket-key state isn't meaningful for them — see the table below instead.
By age — apache/cassandra (last 36 months)
By linked-ticket state — apache/cassandra (last 36 months)
Current month — apache/cassandra
| Month | Open PRs | Drafts | No GitHub response |
|---|---|---|---|
| 2026-09-30 | 15 | 2 | 40% (n=15) |
Based on: CHAOSS: Change Requests (adapted), CHAOSS: Issue Age (adapted, applied to change requests)
Base branch (trunk vs. release branches) is not collected yet, so it is not shown here.
Contributor sustainability
CHAOSS practitioner guide
-
Active Contributors
2
Sep 2026 · n=2
-
New Contributors
0
Sep 2026 · n=0
-
Contributor Dependency (N for 50%)
5
Sep 2026 · n=28
-
Unique Reviewers
3
Sep 2026 · n=3
Contributor Sustainability
Active Contributors
established2 Sep 2026
Based on: CHAOSS: Contributors
New Contributors
established0 Sep 2026
Based on: CHAOSS: New Contributors
First → Second Contribution Conversion
proxyinsufficient data
Based on: CHAOSS: Conversion Rate
Contributor Funnel Conversion
proxy0.0% May 2026 backfill pending
Based on: CHAOSS: Conversion Rate (adjacent), CHAOSS: New Contributors (adjacent)
Contributor Tenure (Kaplan–Meier)
experimentalinsufficient data
Based on: Lin, Robles & Serebrenik (2017), Developer Turnover in Global, Industrial Open Source Projects, Foucault et al. (2015), Impact of Developer Turnover on Quality in Open-Source Software
Contributor Churn Rate
proxy45.0% Aug 2025 backfill pending
Based on: project-specific (no established CHAOSS/literature equivalent)
Sustained Contributors
established9 Sep 2026
Based on: CHAOSS: Contributors (adjacent)
Truck Factor (DOA)
experimental4 Sep 2026
Based on: CHAOSS: Contributor Absence Factor / Bus Factor (adjacent), Avelino, Passos, Hora & Valente (2016), A Novel Approach for Estimating Truck Factors
Contributor Dependency (N for 50%)
established5 Sep 2026
Based on: CHAOSS: Contributor Absence Factor
Contributor Concentration (HHI)
established0.083 Sep 2026
Based on: DOJ/FTC: Herfindahl-Hirschman Index
Reviewer Capacity
Unique Reviewers
proxy3 Sep 2026
Reviewer Concentration (HHI)
proxy0.151 Sep 2026
Based on: project-specific (no established CHAOSS/literature equivalent)
PR Review Engagement (Reviewers/PR)
proxy1.3 Aug 2026
Contributor pipeline
Two additional views of the cards above: a Kaplan–Meier survival curve over contributor tenure, and a per-stage breakdown of the latest completed first-time-contributor cohort's funnel. Both are computed from git commit history only; the committer and PMC funnel stages are not available (no confirmed identity link between the ASF roster and this project's git/JIRA identities exists yet).
Tenure survival
Cohort size (n=27) is below the 30-contributor floor for a Kaplan–Meier curve; showing a still-active count instead.
| Months since first contribution | Eligible | Still active | Share |
|---|---|---|---|
| 3 | 27 | 27 | 100.0% |
| 6 | 19 | 19 | 100.0% |
| 12 | 13 | 13 | 100.0% |
| 18 | 6 | 3 | 50.0% |
| 24 | 0 | 0 | insufficient data |
The contributor funnel isn't published yet.
Contributor leaderboard
Top contributors by one activity type at a time — commits, reviews, and JIRA issues resolved — over the trailing 12 completed months (2025-10-01 to 2026-09-30). These are ranked counts of deterministic, public activity, never a blended "contribution score" and never based on any classified label (DECISIONS.md — D19).
Identity-resolution limits. Counts are grouped by resolved identity (normalize/identity.py), not by human being. M0's identity resolution only merges an exact-matching git email or JIRA username; a commit-trailer reviewer name (a bare handle or display name, not an email) is never automatically linked to that same person's git email or JIRA username, so one contributor active under more than one raw identifier can appear more than once, or under a handle rather than their full name. Manual merges are reviewed, evidenced entries in identity_overrides.yaml -- see the corrections link below to request one. Request an identity correction (every row's own "Report an issue" link below uses this same form) — see /corrections/ for what happens next.
Commits
| # | Contributor | Organization | Count | |
|---|---|---|---|---|
| 1 | Francisco Guerrero | unknown | 23 | Report an issue |
| 2 | N V Harikrishna | unknown | 11 | Report an issue |
| 3 | Jyothsna konisa | unknown | 10 | Report an issue |
| 4 | Jyothsna konisa | Apple | 8 | Report an issue |
| 5 | Jon Haddad | Apple | 8 | Report an issue |
| 6 | Saranya Krishnakumar | Apple | 7 | Report an issue |
| 7 | Paulo Motta | unknown | 6 | Report an issue |
| 8 | Yifan Cai | unknown | 5 | Report an issue |
| 9 | Andrés Beck-Ruiz | Bloomberg | 5 | Report an issue |
| 10 | Shruti Sekaran | unknown | 4 | Report an issue |
| 11 | Arjun Ashok | Apple | 3 | Report an issue |
| 12 | Mansi Khara | unknown | 3 | Report an issue |
| 13 | Sudipta | unknown | 3 | Report an issue |
| 14 | Bernardo Botella | NetApp | 2 | Report an issue |
| 15 | Shailaja Koppu | Apple | 2 | Report an issue |
| 16 | Stefan Miklosovic | Instaclustr | 2 | Report an issue |
| 17 | Brandon Ho | Bloomberg | 1 | Report an issue |
| 18 | Klose6 | unknown | 1 | Report an issue |
| 19 | Lukasz Antoniak | unknown | 1 | Report an issue |
| 20 | Isaac Reath | Bloomberg | 1 | Report an issue |
| 21 | Shalni Sundram | unknown | 1 | Report an issue |
| 22 | bianca-stanciu29 | unknown | 1 | Report an issue |
| 23 | Michael Burman | DataStax | 1 | Report an issue |
| 24 | Shailaja Koppu | Apple | 1 | Report an issue |
| 25 | Paulo Motta | Bloomberg | 1 | Report an issue |
Reviews
| # | Contributor | Organization | Count | |
|---|---|---|---|---|
| 1 | Francisco Guerrero | unknown | 46 | Report an issue |
| 2 | Yifan Cai | unknown | 44 | Report an issue |
| 3 | Saranya Krishnakumar | unknown | 18 | Report an issue |
| 4 | Josh McKenzie | unknown | 17 | Report an issue |
| 5 | Jyothsna Konisa | unknown | 12 | Report an issue |
| 6 | Shailaja Koppu | unknown | 11 | Report an issue |
| 7 | Bernardo Botella | unknown | 10 | Report an issue |
| 8 | Arjun Ashok | unknown | 7 | Report an issue |
| 9 | Paulo Motta | unknown | 7 | Report an issue |
| 10 | Isaac Reath | unknown | 3 | Report an issue |
| 11 | Stefan Miklosovic | unknown | 3 | Report an issue |
| 12 | Saranya Krishnakuma | unknown | 1 | Report an issue |
| 13 | Doug Rohrer | unknown | 1 | Report an issue |
| 14 | James Berragan | unknown | 1 | Report an issue |
| 15 | Jon Haddad | unknown | 1 | Report an issue |
| 16 | Sudipta Laha | unknown | 1 | Report an issue |
| 17 | N V Harikrishna | unknown | 1 | Report an issue |
| 18 | Bernardo Botella Corbi | unknown | 1 | Report an issue |
JIRA issues resolved
| # | Contributor | Organization | Count | |
|---|---|---|---|---|
| 1 | n.v.harikrishna | unknown | 12 | Report an issue |
| 2 | frankgh | unknown | 12 | Report an issue |
| 3 | Jyothsnakonisa | unknown | 11 | Report an issue |
| 4 | paulo | unknown | 6 | Report an issue |
| 5 | bernardo.botella | unknown | 6 | Report an issue |
| 6 | abeckruiz | unknown | 5 | Report an issue |
| 7 | rustyrazorblade | unknown | 5 | Report an issue |
| 8 | ycai | unknown | 4 | Report an issue |
| 9 | shrutips | unknown | 4 | Report an issue |
| 10 | mkhara | unknown | 3 | Report an issue |
| 11 | skoppu | unknown | 3 | Report an issue |
| 12 | saranya_k | unknown | 3 | Report an issue |
| 13 | skrlaha | unknown | 3 | Report an issue |
| 14 | yfl66 | unknown | 2 | Report an issue |
| 15 | arjunashok | unknown | 2 | Report an issue |
| 16 | smiklosovic | unknown | 2 | Report an issue |
| 17 | isaacreath | unknown | 1 | Report an issue |
| 18 | jeetkundoug | unknown | 1 | Report an issue |
| 19 | yuntong | unknown | 1 | Report an issue |
| 20 | brandondho | unknown | 1 | Report an issue |
| 21 | burmanm | unknown | 1 | Report an issue |
| 22 | lukasz.antoniak | unknown | 1 | Report an issue |
| 23 | bstanciu | unknown | 1 | Report an issue |
Organizational participation
CHAOSS practitioner guide
-
Elephant Factor
insufficient data
-
Organizational Concentration (HHI)
insufficient data
-
Single-Organization Share
insufficient data
-
Unknown-Affiliation Rate
63.2%
Sep 2026 · n=114
Organizational Diversity
Elephant Factor
experimentalinsufficient data
Based on: CHAOSS: Elephant Factor, CHAOSS wg-risk: Elephant Factor
Organizational Concentration (HHI)
establishedinsufficient data
Based on: CHAOSS: Organizational Diversity
Single-Organization Share
establishedinsufficient data
Based on: CHAOSS: Organizational Diversity
Unknown-Affiliation Rate
established63.2% Sep 2026
Based on: project-specific (no established CHAOSS/literature equivalent)
Leadership
CHAOSS practitioner guide
-
PMC Joins per Quarter
shared — see Apache Cassandra
PMC membership is tracked once for the whole Apache Cassandra project via the shared ASF roster, not per subproject. See Apache Cassandra's Community page →
Releases
CHAOSS: Release Frequency
-
Release Frequency
4
Sep 2026 · n=4
-
Days Between Releases (median)
175.0 days
Sep 2026 · n=4
-
Time Since Last Release
133.0 days
Oct 2026 · n=1
Release Cadence
Release Frequency
established4 Sep 2026
Based on: CHAOSS: Release Frequency
Release Interval Regularity (CoV)
proxy0.371 Sep 2026
Based on: project-specific (no established CHAOSS/literature equivalent)
Time Since Last Release
established133.0 days Oct 2026
Based on: project-specific (no established CHAOSS/literature equivalent)
Days Between Releases (median)
proxy175.0 days Sep 2026
Based on: CHAOSS: Release Frequency
Conversation patterns
Conversation patterns are classified from the dev@ mailing list, shared across all Apache Cassandra subprojects — not computed per subproject. See Apache Cassandra's Conversations page →