[
https://issues.apache.org/jira/browse/IGNITE-16158?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Maksim Timonin updated IGNITE-16158:
------------------------------------
Description:
```
IgniteCache<Long, Person> cache = crd.createCache("CACHE");
try (IgniteDataStreamer<Long, Person> streamer =
ignite.dataStreamer(cache.getName()))
{ for (int i = 0; i < CNT; i++) streamer.addData((long)i, new
Person(i)); }
IndexQuery<Long, Person> qry = new IndexQuery<Long, Person>(Person.class, IDX)
.setCriteria(lt("id", CNT / 2));
QueryCursor cursor = cache.query(qry.setLocal(true));
cursor.close();
}
```
QueryCursor holds a future that will be completed with iterator over result
data.
Starting a query spawns a new thread that query cache in background, prepares
data, and it completes the future with iterator.
But cancelling of query with `QueryCursor.close` doesn't stops the background
thread, and it will prepare data that will never request. Also cancelling of
query doesn't clean up iterator.
This issue doesn't lead to any memory leaks, and the future and the iterator
will be cleaned up by GC later. But actually we can help to GC by avoiding
preparing the data and by explicit cleaning of those structures.
was:
```
IgniteCache<Long, Person> cache = crd.createCache("CACHE");
try (IgniteDataStreamer<Long, Person> streamer =
ignite.dataStreamer(cache.getName())) {
for (int i = 0; i < CNT; i++)
streamer.addData((long)i, new Person(i));
}
IndexQuery<Long, Person> qry = new IndexQuery<Long, Person>(Person.class, IDX)
.setCriteria(lt("id", CNT / 2));
QueryCursor cursor = cache.query(qry.setLocal(true));
cursor.close();
}
```
QueryCursor holds a future that is completed with iterator over result data.
Starting a query spawns a new thread that query cache in background, prepares
data, and it completes the future with iterator.
But cancelling of query with `QueryCursor.close` doesn't stops the background
thread, and it will prepare data that will never request. Also cancelling of
query doesn't clean up iterator.
This issue doesn't lead to any memory leaks, and the future and the iterator
will be cleaned up by GC later. But actually we can help to GC by avoiding
preparing the data and by explicit cleaning of those structures.
> Cancel of local CacheQuery doesn't stop query
> ---------------------------------------------
>
> Key: IGNITE-16158
> URL: https://issues.apache.org/jira/browse/IGNITE-16158
> Project: Ignite
> Issue Type: New Feature
> Reporter: Maksim Timonin
> Priority: Minor
> Labels: good-first-issue, newbie
>
> ```
> IgniteCache<Long, Person> cache = crd.createCache("CACHE");
> try (IgniteDataStreamer<Long, Person> streamer =
> ignite.dataStreamer(cache.getName()))
> { for (int i = 0; i < CNT; i++) streamer.addData((long)i, new
> Person(i)); }
> IndexQuery<Long, Person> qry = new IndexQuery<Long, Person>(Person.class, IDX)
> .setCriteria(lt("id", CNT / 2));
> QueryCursor cursor = cache.query(qry.setLocal(true));
> cursor.close();
> }
> ```
> QueryCursor holds a future that will be completed with iterator over result
> data.
> Starting a query spawns a new thread that query cache in background, prepares
> data, and it completes the future with iterator.
> But cancelling of query with `QueryCursor.close` doesn't stops the background
> thread, and it will prepare data that will never request. Also cancelling of
> query doesn't clean up iterator.
> This issue doesn't lead to any memory leaks, and the future and the iterator
> will be cleaned up by GC later. But actually we can help to GC by avoiding
> preparing the data and by explicit cleaning of those structures.
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