GitExtensions and Git fail:

      "git" pull --progress "origin"
git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
Done
Press Enter or Esc to exit...

    

But TortoiseGit is OK.

      git.exe pull --progress -v --no-rebase "origin"
From github.com:jinq0123/recastnavigation
= [up to date]      master      -> origin/master
= [up to date]      release-2.0 -> origin/release-2.0
Already up to date.

    

ssh -T shows that the reason is there is no id files:

      PS d:\github> ssh -vT git@github.com
OpenSSH_for_Windows
debug1: Connecting to github.com [20.205.243.166] port 22.
debug1: Connection established.
debug1: identity file C:\\Users\\jinqing/.ssh/id_rsa type -1
debug1: identity file C:\\Users\\jinqing/.ssh/id_xmss-cert type -1
debug1: Authenticating to github.com:22 as 'git'
debug1: Host 'github.com' is known and matches the ED25519 host key.
debug1: Found key in C:\\Users\\jinqing/.ssh/known_hosts:2
debug1: Will attempt key: C:\\Users\\jinqing/.ssh/id_rsa
debug1: Will attempt key: C:\\Users\\jinqing/.ssh/id_xmss
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: C:\\Users\\jinqing/.ssh/id_rsa
debug1: Trying private key: C:\\Users\\jinqing/.ssh/id_xmss
debug1: No more authentication methods to try.
git@github.com: Permission denied (publickey).
PS d:\github>

    

Copy my RSA key file rsa.ppk that TortoiseGit uses as ~/.ssh/id_rsa:

      PS D:\jinqing\github_jinq\recastnavigation> ssh -T git@github.com
Load key "C:\\Users\\jinqing/.ssh/id_rsa": invalid format
git@github.com: Permission denied (publickey).
PS D:\jinqing\github_jinq\recastnavigation>

    

Open TortoiseGit/bin/puttygen.exe, load rsa.ppk, then Convensionis->Export OpenSSH key as ~/.ssh/id_rsa:

      PS D:\jinqing\github_jinq\recastnavigation> ssh -T git@github.com
Hi jinq0123! You've successfully authenticated, ...

    

id_rsa begins with:

      -----BEGIN RSA PRIVATE KEY-----

    

(Jin Qing's Column, Dec., 2021)

Try to find out why Orleans need a DeathVoteExpirationTimeout config.

https://dotnet.github.io/orleans/docs/implementation/cluster_management.html#extension-to-totally-order-membership-views

DeathVoteExpirationTimeout - Expiration time in seconds for death vote in the membership table. Default is 120 seconds

GetFreshVotes

DeathVoteExpirationTimeout is only used by GetFreshVotes(), which has 3 occurence:

    class ClusterHealthMonitor
    {
        ...
        private UpdateMonitoredSilos(...)
        {
            ...
            bool isSuspected = candidateEntry.GetFreshVotes(now, DeathVoteExpirationTimeout).Count > 0;
            ...
        }
    }

    class LocalSiloHealthMonitor
    {
        ...
        private int CheckSuspectingNodes(DateTime now, List<string> complaints)
        {
            ...
            var freshVotes = membershipEntry.GetFreshVotes(now, DeathVoteExpirationTimeout);
            ...
        }
        ...
    }

    class MembershipTableManager
    {
        ...
        public TryToSuspectOrKill(SiloAddress silo)
        {
            ...
            // get all valid (non-expired) votes
            var freshVotes = entry.GetFreshVotes(DateTime.UtcNow, DeathVoteExpirationTimeout);
            ...
        }
        ...
    }

GetFreshVotes() uses this expiration time to ignore old voter:

        internal GetFreshVotes(DateTime now, TimeSpan expiration)
        {
            ...
            foreach (var voter in this.SuspectTimes)
            {
                var otherVoterTime = voter.Item2;
                if (now.Subtract(otherVoterTime) < expiration)
                {
                    result.Add(voter);
                }
            }
            return result.ToImmutable();
        }

金庆 2021-12-08 09:43 发表评论

]]>

(Jin Qing's Column, Dec., 2021)

GitExtension is a good tool. After a long time of usage, my branch list finally reaches over a full screen, and it is hard to select the branch I want.

GitExtension always remembers all the branches of remote and local, even they have been deleted.

I tried to find a way to delete these branches which are already merged, but resulted in futile.

It has a plugin names "Delete obsolete branches", but I don't know how to use it.

Finally I renamed the work directory, and cloned a new one, which clears all the branches. It seems that these branches are stored in local .git directory. If let GitExt open the renamed directory, these branches reappears.

Reference:

• https://talk.plesk.com/threads/git-extension-doesnt-remove-deleted-branches.351838/
• https://plesk.uservoice.com/forums/184549-feature-suggestions/suggestions/39296707-git-extension-option-to-delete-branches

(Jin Qing's Column, Nov. 3, 2021)

When deployed to a cluster of nodes, Orleans internally implements a protocol to manage it's silos, including discovery, failure and reconfigure, which is called cluster membership management.

Orleans has clustering membership providers for: Azure, SQL server, Zookeeper.

Clustering provider is one of key aspects of silo configuration.

Orleans.Clustering.Kubernetes

OrleansContrib/Orleans.Clustering.Kubernetes is a clustering provider for running Orleans cluster on Kubernetes.

Tell silo to use Kubernetes as the Cluster Membership Provider:

var silo = new SiloBuilder()
        ...
        .UseKubeMembership()
        ...
        .Build();

Interface

UseKubeMembership() instantiates a KubeMembershipTable which implements IMembershipTable.

    public interface IMembershipTable
    {
        Task InitializeMembershipTable(bool tryInitTableVersion);
        Task DeleteMembershipTableEntries(string clusterId);
        Task CleanupDefunctSiloEntries(DateTimeOffset beforeDate);
        Task<MembershipTableData> ReadRow(SiloAddress key);
        Task<MembershipTableData> ReadAll();
        Task<bool> InsertRow(MembershipEntry entry, TableVersion tableVersion);
        Task<bool> UpdateRow(MembershipEntry entry, string etag, TableVersion tableVersion);
        Task UpdateIAmAlive(MembershipEntry entry);
    }

Implement

KubeMembershipTable access Kubernetes API server to read and write silo entry CRD.

• InitializeMembershipTable()

  • TryInitClusterVersion()

    • _kubeClient.GetNamespacedCustomObjectAsync
    • _kubeClient.CreateNamespacedCustomObjectAsync

• DeleteMembershipTableEntries(string clusterId)

  • _kubeClient.DeleteNamespacedCustomObjectAsync

• InsertRow(...)

  • _kubeClient.GetNamespacedCustomObjectAsync
  • _kubeClient.ReplaceNamespacedCustomObjectAsync
  • _kubeClient.CreateNamespacedCustomObjectAsync

• ReadAll()

  • GetClusterVersion()

    • _kubeClient.ListNamespacedCustomObjectAsync

  • GetSilos()

    • _kubeClient.ListNamespacedCustomObjectAsync

• ReadRow(SiloAddress key)

  • _kubeClient.GetNamespacedCustomObjectAsync

• UpdateIAmAlive(MembershipEntry entry)

  • _kubeClient.GetNamespacedCustomObjectAsync
  • _kubeClient.ReplaceNamespacedCustomObjectAsync

• UpdateRow(...)

  • _kubeClient.ReplaceNamespacedCustomObjectAsync

• CleanupDefunctSiloEntries(DateTimeOffset beforeDate)

  • _kubeClient.DeleteNamespacedCustomObjectAsync

The operators to NamespacedCustomObject are:

• Delete
• Get
• Create
• Replace
• List

CRD

Two CRDs, ClusterVersion and Silo are defined in files:

• ClusterVersionCRD.yaml
• SiloEntryCRD.yaml

Custom resource objects are stored in etcd of Kubernetes.

(Jin Qing's Column, Nov. 2, 2021)

Virtual Actor is a concept invented by Microsoft Orleans, which is a framework of distributed actor.

Orleans: Distributed Virtual Actors for Programmability and Scalability describes the virtual programming model.

The virtual actor is analogous to virtual memory. Virtual actors are mapped to physical arctors instances in the running servers. Virtualization of actors in Orleans has 4 facets:

1. Perpetual existence

   • Actors always exist, virtually
   • Actors can not be created or destroied explicitly
   • Server failure does not affect the actors' existence

2. Automatic instantiation

   • Activation: Orleans automatically create an actor
   • A request triggers an activation if the actor doesn't exist
   • Unused actors are automatically reclaimed

3. Location transparency

   • Applications don't know where the physical actor is
   • Similar to virtual memory's "paged out" and mapping

4. Automatic scale out

   • 2 activation modes:

     • Single activation (default): Only one simultaneous actor is allowed

     • Stateless worker: Many activations of an actor are created

       • to increase throughput

Actor viruliaztion greatly simplifes the programming, since it gets rid of the burden of actor lifecycle control.

(Jin Qing's Column, Oct. 25, 2021)

Reading "The Evolution of Distributed Systems on Kubernetes" from Bilgin Ibryam.

https://www.infoq.com/articles/distributed-systems-kubernetes/

What are the purpose of projects like Dapr, Istio, Knative? How can they change the world?

Modern distributed systems

The needs of distributed systems:

• Business logic

• Other

  • Lifecycle: deploy, rollback, upgrade, scale, stop, isolate, config
  • Network: connect, circuit break, retry, timeout, load balance, discover, security, trace
  • Resource binding: to API, protocol, message, data format
  • State: stateless, stateful, store

Monolithic architecture

enterprise service bus (ESB): not distributed

Cloud-native architecture

Kubernetes: Lifecycle

Service Mesh

Istio: Networking

Serverless

Knative: scale

Dapr

Networking, resource binding, state

Trends

• Lifecycle: Kubernetes + operator
• Networking: Envoy
• Binding: Apache Camel
• State: Cloudstate

Multi-runtime microservice

Write business logic as another runtime. Here runtime is a process?

What comes after microservice

Faas is not the best. Multi-runtime microservice maybe is.

Mecha architecture

• Never use unwrap on Result. If the type is Err, it will panic and crash the program. The only exception is if it has already been checked for error previously or in test code.
• Never use unwrap on Option for the same reason if the type is None as Result is Err.

pub(in path), pub(crate), pub(super), and pub(self)

In addition to public and private, Rust allows users to declare an item as visible only within a given scope. The rules for pub restrictions are as follows:

• pub(in path) makes an item visible within the provided path. path must be an ancestor module of the item whose visibility is being declared.
• pub(crate) makes an item visible within the current crate.
• pub(super) makes an item visible to the parent module. This is equivalent to pub(in super).
• pub(self) makes an item visible to the current module. This is equivalent to pub(in self) or not using pub at all.

(金庆的专栏 2017.11)

go get 功能比较弱，无法获取分支，标签，特定版本，fork, 而 dep 可以做到。dep 还可以获取私有库。

用 gitee.com 私有库作测试。创建 gogettest 库。

可用：

go get -u gitee.com/jinq0123/gogettest

如果改为私有库则失败：

λ go get -v gitee.com/jinq0123/gogettest
Fetching https://gitee.com/jinq0123/gogettest?go-get=1
Parsing meta tags from https://gitee.com/jinq0123/gogettest?go-get=1 (status code 403)
package gitee.com/jinq0123/gogettest: unrecognized import path "gitee.com/jinq0123/gogettest" (parse https://gitee.com/jinq0123/gogettest?go-get=1: no go-import meta tags ())

用 dep 工具取私有库

https://github.com/golang/dep

安装dep

go get -u github.com/golang/dep/cmd/dep1

初始化

在项目目录下运行：

dep init

生成 Gopkg.toml 和 Gopkg.lock

添加强制(constraint)

在 Gopkg.toml 中添加：

注意库名改成了 jinq012345, 这样导入：
imort "gitee.com/jinq012345/gogettest"

name和source的设置可支持从 fork 库获取。

获取gogettest库

dep ensure

会弹出 https 的登录用户名和密码输入框。