Ok, let's add simple reconnect logic and see what will come of it. On Thu, Feb 1, 2018 at 12:49 AM, Dmitriy Setrakyan <dsetrak...@apache.org> wrote:
> Pavel, > > I disagree. I think automatic reconnect is a very useful feature. For > example, all client-side operation can throw exception anyway, so if you > throw an exception due to a client reconnect, it will not require any > additional exception-handling logic. > > On the other hand, after a few failed operations in case of a reconnect, > the client will continue to operate normally. This will make our clients > resilient to failures and make it way more powerful. > > I strongly vote to add this behavior. > > D. > > > On Wed, Jan 31, 2018 at 3:15 AM, Pavel Tupitsyn <ptupit...@apache.org> > wrote: > > > Alexey, retrieving addresses from topology makes sense, but in this > thread > > I'm trying to understand whether any kind of built-in failover > > makes sense at all at the Ignite API level. > > > > I mean, on the business logic level failover certainly makes sense: > > if Web Agent has failed to execute some operation, it can show an error, > > automatically reconnect to another node and continue working. > > > > But on the Ignite API level it gets questionable. We can implement some > > failover/reconnect logic, but users still has to handle failed operations > > themselves. > > > > Pavel > > > > On Wed, Jan 31, 2018 at 2:08 PM, Alexey Kuznetsov <akuznet...@apache.org > > > > wrote: > > > > > Pavel, > > > > > > I hope, that at some point Web agent (connector to Web Console) will be > > > refactored from REST to thin client. > > > > > > It will be nice if thin client will support following modes: > > > 1) Specify several addresses in thin client connection config. Thin > > client > > > will use ONLY this addresses (hardcoded list). > > > 2) Same as #1, but in addition to specified list of addresses thin > client > > > collect list of "connectable" nodes from topology (extendable list). > > > > > > What do you think? > > > > > > > > > On Wed, Jan 31, 2018 at 5:14 PM, Pavel Tupitsyn <ptupit...@apache.org> > > > wrote: > > > > > > > Igniters, > > > > > > > > I'm working on client-side failover logic for .NET Thin Client. > > > > This will probably apply to ODBC and JDBC thin clients as well in > > future. > > > > > > > > Currently all thin clients connect to a single specified Ignite node. > > > > The idea is to have multiple known nodes (host:port pairs) and > > reconnect > > > > to another node if current one goes down. > > > > > > > > Problems: > > > > - Protocol is stateful, server keeps track of query cursors for the > > > session > > > > - Many operations are not idempotent, so retry is not an option > > > > - Async operations and multithreading are supported in .NET thin > client > > > > > > > > So while we can detect socket connection failure and reconnect to a > > > > different node, > > > > all currently executing client operations and query cursors will > still > > > fail > > > > with an exception. > > > > > > > > I'm not sure how useful this behavior will be. > > > > Any thoughts, ideas? > > > > > > > > Thanks, > > > > Pavel > > > > > > > > > > > > > > > > -- > > > Alexey Kuznetsov > > > > > >
