Pod 容忍节点异常时间调整 容忍节点异常时间调整 1. 原理说明 原理说明 Kubernetes 集群节点处于异常状态之后需要有⼀个等待时间，才会对节点上的 Pod 进⾏驱逐。那么针对部分关键业务，是否可以调整这个时间，便于在节点发⽣异常时及时将 Pod 驱逐 并在别的健康节点上重建？ 要解决这个问题，我们⾸先要了解 Kubernetes 在节点异常时驱逐 Pod 的机制。 在 Kubernetes 这两个 feature gate，节点及其上 Pod 的⽣命周期管理将通过节点的 Condition 和 Taint 来进⾏，Kubernetes 会不断地检查所有节点状态，设置对应的 Condition，根据 Condition 为节点设置对应的 Taint，再根据 Taint 来驱逐节点上的 Pod。 同时在创建 Pod 时会默认为 Pod 添加相应的 tolerationSeconds tolerationSeconds 参数，指定当节点出现异常（如 NotReady）时 Pod 还将在这个节点上运⾏多⻓的时间。 那么，节点发⽣异常到 Pod 被驱逐的时间，就取决于两个参数：1. 节点实际异常到被判断为不健康的时间；2. Pod 对节点不健康的容忍时间。 Kubernetes 集群中默认节点实际异常到被判断为不健康的时间为 40s，Pod 对节点 NotReady 的容忍时间为 5min，也就是说，节点实际异常

time. Do not hold on to them past the duration of the current function, or stow them away inside structs. If you need to keep the object for longer than that, you have to either keep it or make your own into C++ exceptions. 5.1.3 Class-aware C++ API C++ wrapper classes wrap most fz_* and pdf_* C structs. • Class names are camel-case versions of the wrapped struct’s name, for example fz_document’s wrapper class is mupdf::FzDocument. • Classes automatically handle reference counting of the underlying C structs, so there is no need for manual calls to fz_keep_*() and fz_drop_*(), and class instances can be

time. Do not hold on to them past the duration of the current function, or stow them away inside structs. If you need to keep the object for longer than that, you have to either keep it or make your own into C++ exceptions. 7.1.3 Class-aware C++ API C++ wrapper classes wrap most fz_* and pdf_* C structs. • Class names are camel-case versions of the wrapped struct’s name, for example fz_document’s wrapper class is mupdf::FzDocument. • Classes automatically handle reference counting of the underlying C structs, so there is no need for manual calls to fz_keep_*() and fz_drop_*(), and class instances can be

time. Do not hold on to them past the duration of the current function, or stow them away inside structs. If you need to keep the object for longer than that, you have to either keep it or make your own into C++ exceptions. 7.1.3 Class-aware C++ API C++ wrapper classes wrap most fz_* and pdf_* C structs. • Class names are camel-case versions of the wrapped struct’s name, for example fz_document’s wrapper class is mupdf::FzDocument. • Classes automatically handle reference counting of the underlying C structs, so there is no need for manual calls to fz_keep_*() and fz_drop_*(), and class instances can be

time. Do not hold on to them past the duration of the current function, or stow them away inside structs. If you need to keep the object for longer than that, you have to either keep it or make your own into C++ exceptions. 8.2.3 Class-aware C++ API C++ wrapper classes wrap most fz_* and pdf_* C structs: • Class names are camel-case versions of the wrapped struct’s name, for example fz_document’s wrapper class is mupdf::FzDocument. • Classes automatically handle reference counting of the underlying C structs, so there is no need for manual calls to fz_keep_*() and fz_drop_*(), and class instances can be

The C++ implementation will create expressive API calls through utilizing combination of : ▪POD structs -- structs with data members only ▪designated initializers -- initializing a struct with: { .field = the road state -- There is only one. // the .= syntax is a designated initializer used to assign POD values auto result = processCarStateTransition({ .car = Car::FastSportsCar, .startingRoadState nextRoadState = { .type = RoadType::Avenue,.speed = Speed::NORMAL}}); Ambiguity The following structs will in theory dispatch to processCarStateTransition depending on how you call them. Non-Ambiguous

variables, and function static variables, must be Plain Old Data (POD): only ints, chars, floats, or pointers, or arrays/structs of POD. The order in which class constructors and initializers for static function (such as getenv(), or getpid()) does not itself depend on any other globals. However, a static POD variable within function scope may be initialized with the result of a function, since its initialization quick_exit(), you need to register it in both places.) As a result we only allow static variables to contain POD data. This rule completely disallows vector (use C arrays instead), or string (use const char []).

14 Aside: POD Types  Standard-layout types are defined in C++11.  The 2003 Standard didn’t mention standard-layout types — it describes layout guarantees in terms of POD types.  POD stands for “Plain (There’s also a POF.)  A POD is a standard-layout class that also lacks:  private or protected non-static data members  user-declared constructors  base classes  In practice, POD classes are too restrictive Type type_; short x_, y_; }; void draw(Shape *); void rotate(Shape *, int);  Here, we’re using structs and non-member functions.  We could just as well use classes and static member functions. 97 Copyright

constructor, destructor, or copy assignment operator… This definition is essentially the same as a C++03 POD type. armv7-a System V x86 System V x86 Microsoft A Composite Type not larger than 4 bytes is returned 16 bytes x86 System V fundamental only x86-64 Microsoft 1,2,4,8 bytes, C++03 POD x86 Microsoft 1,2,4,8 bytes, C++03 POD Composite types are required to be “trivial” to get into registers!C.20: If you ___$ReturnUdt$[esp-4] mov DWORD PTR [eax], 60 mov DWORD PTR [eax+4], 0 ret 0 C H R 67 not a POD not a POD size > 4 not fundamentalCan we do something about it? ● std::chrono would have to give up encapsulation

to either Kotlin enum or integral values, depending on heuristics and the de�nition �le hints. Structs / unions are mapped to types having �elds available via the dot notation, i.e. someStructInstance simple immutable self-contained value. Think C++ references, as a similar concept. For structs (and typedef s to structs) this representation is the main one and has the same name as the struct itself, for runtime by calling kotlin.native.initRuntimeIfNeeded() . Scope-local pointers Passing and receiving structs by value — — Callbacks Passing user data to callbacks 405 Often C APIs allow passing some user