Good points, Sergey. Maybe you are right, and Java-based compute without peer deployment is a good first step for thin clients.
On Thu, Nov 21, 2019 at 12:32 PM Sergey Kozlov <skoz...@gridgain.com> wrote: > Hi Pavel > > On Thu, Nov 21, 2019 at 11:30 AM Pavel Tupitsyn <ptupit...@apache.org> > wrote: > > > 1. I believe that Cluster operations for Thin Client protocol are already > > in the works > > by Alexandr Shapkin. Can't find the ticket though. > > Alexandr, can you please confirm and attach the ticket number? > > > > 2. Proposed changes will work only for Java tasks that are already > deployed > > on server nodes. > > This is mostly useless for other thin clients we have (Python, PHP, .NET, > > C++). > > > > I don't guess so. The task (execution) is a way to implement own layer for > the thin client application. > > > > We should think of a way to make this useful for all clients. > > For example, we may allow sending tasks in some scripting language like > > Javascript. > > Thoughts? > > > > The arbitrary code execution from a remote client must be protected > from malicious code. > I don't know how it could be designed but without that we open the hole to > kill cluster. > > > > > > On Thu, Nov 21, 2019 at 11:21 AM Sergey Kozlov <skoz...@gridgain.com> > > wrote: > > > > > Hi Alex > > > > > > The idea is great. But I have some concerns that probably should be > taken > > > into account for design: > > > > > > 1. We need to have the ability to stop a task execution, smth like > > > OP_COMPUTE_CANCEL_TASK operation (client to server) > > > 2. What's about task execution timeout? It may help to the cluster > > > survival for buggy tasks > > > 3. Ignite doesn't have roles/authorization functionality for now. > But > > a > > > task is the risky operation for cluster (for security reasons). > Could > > we > > > add for Ignite configuration new options: > > > - Explicit turning on for compute task support for thin protocol > > > (disabled by default) for whole cluster > > > - Explicit turning on for compute task support for a node > > > - The list of task names (classes) allowed to execute by thin > > client. > > > 4. Support the labeling for task that may help to investigate issues > > on > > > cluster (the idea from IEP-34 [1]) > > > > > > 1. > > > > > > > > > https://cwiki.apache.org/confluence/display/IGNITE/IEP-34+Thin+client%3A+transactions+support > > > > > > > > > > > > On Thu, Nov 21, 2019 at 10:58 AM Alex Plehanov < > plehanov.a...@gmail.com> > > > wrote: > > > > > > > Hello, Igniters! > > > > > > > > I have plans to start implementation of Compute interface for Ignite > > thin > > > > client and want to discuss features that should be implemented. > > > > > > > > We already have Compute implementation for binary-rest clients > > > > (GridClientCompute), which have the following functionality: > > > > - Filtering cluster nodes (projection) for compute > > > > - Executing task by the name > > > > > > > > I think we can implement this functionality in a thin client as well. > > > > > > > > First of all, we need some operation types to request a list of all > > > > available nodes and probably node attributes (by a list of nodes). > Node > > > > attributes will be helpful if we will decide to implement analog of > > > > ClusterGroup#forAttribute or ClusterGroup#forePredicate methods in > the > > > thin > > > > client. Perhaps they can be requested lazily. > > > > > > > > From the protocol point of view there will be two new operations: > > > > > > > > OP_CLUSTER_GET_NODES > > > > Request: empty > > > > Response: long topologyVersion, int minorTopologyVersion, int > > nodesCount, > > > > for each node set of node fields (UUID nodeId, Object or String > > > > consistentId, long order, etc) > > > > > > > > OP_CLUSTER_GET_NODE_ATTRIBUTES > > > > Request: int nodesCount, for each node: UUID nodeId > > > > Response: int nodesCount, for each node: int attributesCount, for > each > > > node > > > > attribute: String name, Object value > > > > > > > > To execute tasks we need something like these methods in the client > > API: > > > > Object execute(String task, Object arg) > > > > Future<Object> executeAsync(String task, Object arg) > > > > Object affinityExecute(String task, String cache, Object key, Object > > arg) > > > > Future<Object> affinityExecuteAsync(String task, String cache, Object > > > key, > > > > Object arg) > > > > > > > > Which can be mapped to protocol operations: > > > > > > > > OP_COMPUTE_EXECUTE_TASK > > > > Request: UUID nodeId, String taskName, Object arg > > > > Response: Object result > > > > > > > > OP_COMPUTE_EXECUTE_TASK_AFFINITY > > > > Request: String cacheName, Object key, String taskName, Object arg > > > > Response: Object result > > > > > > > > The second operation is needed because we sometimes can't calculate > and > > > > connect to affinity node on the client-side (affinity awareness can > be > > > > disabled, custom affinity function can be used or there can be no > > > > connection between client and affinity node), but we can make best > > effort > > > > to send request to target node if affinity awareness is enabled. > > > > > > > > Currently, on the server-side requests always processed synchronously > > and > > > > responses are sent right after request was processed. To execute long > > > tasks > > > > async we should whether change this logic or introduce some kind > > two-way > > > > communication between client and server (now only one-way requests > from > > > > client to server are allowed). > > > > > > > > Two-way communication can also be useful in the future if we will > send > > > some > > > > server-side generated events to clients. > > > > > > > > In case of two-way communication there can be new operations > > introduced: > > > > > > > > OP_COMPUTE_EXECUTE_TASK (from client to server) > > > > Request: UUID nodeId, String taskName, Object arg > > > > Response: long taskId > > > > > > > > OP_COMPUTE_TASK_FINISHED (from server to client) > > > > Request: taskId, Object result > > > > Response: empty > > > > > > > > The same for affinity requests. > > > > > > > > Also, we can implement not only execute task operation, but some > other > > > > operations from IgniteCompute (broadcast, run, call), but it will be > > > useful > > > > only for java thin client. And even with java thin client we should > > > whether > > > > implement peer-class-loading for thin clients (this also requires > > two-way > > > > client-server communication) or put classes with executed closures to > > the > > > > server locally. > > > > > > > > What do you think about proposed protocol changes? > > > > Do we need two-way requests between client and server? > > > > Do we need support of compute methods other than "execute task"? > > > > What do you think about peer-class-loading for thin clients? > > > > > > > > > > > > > -- > > > Sergey Kozlov > > > GridGain Systems > > > www.gridgain.com > > > > > > > > -- > Sergey Kozlov > GridGain Systems > www.gridgain.com >
