[
https://issues.apache.org/jira/browse/TINKERPOP-1035?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15048472#comment-15048472
]
ASF GitHub Bot commented on TINKERPOP-1035:
-------------------------------------------
GitHub user spmallette opened a pull request:
https://github.com/apache/incubator-tinkerpop/pull/174
TINKERPOP-1035 Improved consistency of transaction management in gremlin
server.
https://issues.apache.org/jira/browse/TINKERPOP-1035
Sessionless requests now have special handling for `GraphTraversal` return
results. Gremlin Server now force iterates those results (when they include
`Mutating` steps) to a `List`. It then commits and then iterates that `List`.
For all other results the commit occurs in the same spot, but doesn't force
iterate which allows results to stream as they always have.
Tested manually and with:
```text
mvn clean install
mvn verify -DskipIntegrationTests=false -pl gremlin-server
```
VOTE: +1
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/apache/incubator-tinkerpop TINKERPOP-1035
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/incubator-tinkerpop/pull/174.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #174
----
commit dbc7f94c343f5ca8d4e51c0354280b552c231967
Author: Stephen Mallette <[email protected]>
Date: 2015-12-09T00:50:18Z
Improved consistency of transaction management in gremlin server.
Sessionless requests now have special handling for GraphTraversal return
results. Gremlin Server now force iterates those results (when they include
Mutating steps) to a List. It then commits and then iterates that List. For
all other results the commit occurs in the same spot, but doesn't force iterate
which allows results to stream as they always have.
----
> Better Consistency in Gremlin Server Transaction Management
> ------------------------------------------------------------
>
> Key: TINKERPOP-1035
> URL: https://issues.apache.org/jira/browse/TINKERPOP-1035
> Project: TinkerPop
> Issue Type: Improvement
> Components: server
> Affects Versions: 3.1.0-incubating
> Reporter: stephen mallette
> Assignee: stephen mallette
> Fix For: 3.1.1-incubating
>
>
> For sessionless requests, Gremlin Server currently calls commit after
> iteration of results is complete. The problem is that if the user issues:
> {{g.addV()}} then a graph may not have assigned proper identifiers at that
> point (or have other issues) at the time of serialization. Gremlin Server
> also then spends time sending back results (if it can) when a call to
> {{commit()}} will ultimately fail.
> A solution that seems to work is to move the {{commit()}} to occur after eval
> but before iteration of results to the client. Moreover, if the result to be
> iterated is a {{Traversal}} then we can check if it has {{Mutating}} steps
> and if so, iterate it out first to {{List}}, call {{commit()}} and then
> iterate the {{List}}. The obvious downside is that we lose streaming in
> these cases as the result has to be held in memory.
> For now, I think we need to take the downside as there aren't any other
> solutions that work consistently across all graphs. For 3.2.x and forward we
> can think of better fixes that might introduce some breaking change.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
