# open-questions Published articles for open-questions. This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## 【kube-apiserver】选型收束与开放问题：排除树、Kine 与 events 分集群 DevFeed: [【kube-apiserver】选型收束与开放问题：排除树、Kine 与 events 分集群]() Original publisher: [Read original article]() Author: Liao Tonglang Published: 2026-08-28T00:00:00Z Content type: tutorial Language: zh Sources: [土法炼钢 - 系统与基础设施]() Topics: [Kubernetes](), [Caching](), [etcd](), [SQL](), [MySQL](), [PostgreSQL](), [SQLite](), [Raft]() Tags: [apiserver](), [churn](), [distributed](), [errcompacted](), [etcd](), [events](), [exclusion-tree](), [kine](), [kubernetes](), [mysql](), [open-questions](), [postgresql](), [quota](), [raft](), [selection](), [sql](), [sqlite](), [storage](), [ttl](), [v1-30-3](), [watch-cache]() ### AI overview This concluding article presents a mechanism-based decision tree for diagnosing Kubernetes control-plane issues across kube-apiserver and etcd layers. It explains Kine's differing Watch semantics when using SQLite, PostgreSQL, or MySQL backends, discusses routing Kubernetes Events to a separate etcd cluster, and identifies open questions around watch-cache SLOs, compaction, linear reads, and Lease fencing. ### Source excerpt 用机制排除树收束何时查 apiserver 轴、何时穿透 etcd 轴、何时两轴联查；回收 etcd/13 写下的 apiserver 停损线；Kine SQL backend 的 Watch 语义差与 Jepsen 覆盖空白；events --etcd-servers-overrides 分集群运维；列出 watch cache SLO 联合模型、线性读期望与 Lease+fencing 全链路三个开放问题；以 ADR 语言关闭系列边界。 ## 【etcd】选型收束与开放问题：排除树与系列边界关闭 DevFeed: [【etcd】选型收束与开放问题：排除树与系列边界关闭]() Original publisher: [Read original article]() Author: Liao Tonglang Published: 2026-08-26T00:00:00Z Content type: article Language: zh Sources: [土法炼钢 - 系统与基础设施]() Topics: [etcd](), [Raft](), [Kubernetes]() Tags: [apiserver](), [backup](), [compaction](), [distributed](), [etcd](), [exclusion-tree](), [foundationdb](), [guide](), [k8s](), [kubernetes](), [lease](), [open-questions](), [raft](), [selection](), [tikv](), [v3](), [v3-5-33](), [zookeeper]() ### AI overview This concluding article presents a mechanism-based decision tree for deciding when to retain etcd and when to migrate to TiKV or FoundationDB. It defines etcd's fit for small data sets with Watch and Lease dependencies, identifies disqualifying conditions such as quota pressure, sharding needs, cross-key transactions, Watch backpressure, and insufficient operational capacity, and clarifies the boundaries between related article series. ### Source excerpt 用机制排除树收束何时该留 etcd、何时迁 TiKV/FDB/ZK；回收 distributed/39、tikv-htap/18、foundationdb/18 的 etcd 叶；列出 Watch 背压、Lease+fencing、quota 迁移等开放问题；以 ADR 语言关闭续作边界。 ## History of SpaceX: Synthesis, the Independence Assumption, and Projection through 2050 DevFeed: [History of SpaceX: Synthesis, the Independence Assumption, and Projection through 2050]() Original publisher: [Read original article]() Author: Brendan Sechter Published: 2026-08-05T09:00:00Z Content type: opinion Language: en Sources: [Brendan A R Sechter's Development Blog]() Topics: [Framework]() Tags: [aerospace](), [analysis](), [business](), [framework](), [history](), [open-questions](), [projection]() ### AI overview This concluding article in a History of SpaceX series retrospectively assesses the series' framework, argues that its supposedly separable conditions are coupled, and examines how that independence assumption affects assessment. It also projects the analysis to 2050 under stated assumptions, ranks failure modes, and identifies unresolved questions. ### Source excerpt This article closes the History of SpaceX series. It has three tasks. The first is retrospective, restating the seven forcing-function conditions and the three capital-formation legs that the series opener introduced and that the intervening ten articles developed, and assessing what each turned out to establish. The second is critical, and it is the article's principal contribution. Across three independent articles the series encountered the same structural surprise, namely that conditions the framework treats as separable are in fact coupled, and the closing article argues that the coupling is general and not incidental and that the framework's independence assumption biases the assessment in opposite directions depending on the state of the world. The third is projective, extending the analysis to 2050 under explicitly stated assumptions and with the failure modes ranked, not merely listed. The article treats the alternative contemporary configurations that the commentary offers as templates, comprising the defense-technology venture, the failed-governance case, the intelligence-anchor case, and the patient-single-funder case, and the deep historical precedents comprising the industrial consolidation, the corporate research laboratory, the endowed foundation, the mass-production firm, and the early aircraft manufacturers. The article closes with the load-bearing open questions the series as a whole leaves unresolved, which are more numerous than any single article's closing section suggested. The Synthesis Problem The mapping problem for a closing article differs from that of the eleven that precede it. Those articles each asked what happened along one dimension. This one asks whether the dimensions were the right ones, whether the framework built from them holds together, and what it predicts. The series advanced a thesis, which the series opener states as the singular-conjunction claim. The claim is that a particular venture is the only modern case satisfying ## Other Complexity Classes DevFeed: [Other Complexity Classes]() Original publisher: [Read original article]() Published: 2012-02-29T17:12:35Z Content type: article Language: en Sources: [Jeremy Kun]() Topics: [Algorithms, Complexity](), [Computing](), [Math and Logic]() Tags: [complexity](), [computational-complexity](), [halting-problem](), [kolmogorov-complexity](), [nondeterminism](), [open-questions](), [oracle](), [primer](), [pspace](), [turing-machine](), [turing-machines]() ### AI overview This article introduces complexity classes beyond P and NP, including PSPACE and NPSPACE, and discusses oracle-based classes. It explains that PSPACE equals NPSPACE while many relationships among complexity classes remain open. ### Source excerpt Not Just Time, But Space Too! So far on this blog we've introduced models for computation, focused on Turing machines and given a short overview of the two most fundamental classes of problems: P and NP. While the most significant open question in the theory of computation is still whether P = NP, it turns out that there are hundreds (almost 500, in fact!) other "classes" of problems whose relationships are more or less unknown.