Question

我正在运行一个设置，我使用安装neo4j-jdbc驱动程序的jdbc API连接到VM中的neo4j数据库，并且在执行一些多线程工作时遇到了死锁问题。我想知道是否有人知道neo4j-jdbc驱动程序3.x是否是线程安全的？

错误记录

Exception: java.sql.BatchUpdateException: org.neo4j.driver.v1.exceptions.TransientException: LockClient[4211] can't wait on resource RWLock[NODE(2410), hash=1674994875] since => LockClient[4211] <-[:HELD_BY]- RWLock[NODE(2403), hash=1544505462] <-[:WAITING_FOR]- LockClient[4205] <-[:HELD_BY]- RWLock[NODE(2410), hash=1674994875]
org.neo4j.jdbc.bolt.BoltPreparedStatement.executeBatch(BoltPreparedStatement.java:178)
org.apache.commons.dbcp2.DelegatingStatement.executeBatch(DelegatingStatement.java:345)
org.apache.commons.dbcp2.DelegatingStatement.executeBatch(DelegatingStatement.java:345)
org.apache.beam.sdk.io.jdbc.JdbcIO$Write$WriteFn.finishBundle(JdbcIO.java:480)
Caused By: org.neo4j.driver.v1.exceptions.TransientException: LockClient[4211] can't wait on resource RWLock[NODE(2410), hash=1674994875] since => LockClient[4211] <-[:HELD_BY]- RWLock[NODE(2403), hash=1544505462] <-[:WAITING_FOR]- LockClient[4205] <-[:HELD_BY]- RWLock[NODE(2410), hash=1674994875]
org.neo4j.driver.internal.connector.socket.SocketResponseHandler.handleFailureMessage(SocketResponseHandler.java:71)
org.neo4j.driver.internal.messaging.PackStreamMessageFormatV1$Reader.unpackFailureMessage(PackStreamMessageFormatV1.java:464)
org.neo4j.driver.internal.messaging.PackStreamMessageFormatV1$Reader.read(PackStreamMessageFormatV1.java:425)
org.neo4j.driver.internal.connector.socket.SocketClient.receiveOne(SocketClient.java:130)
org.neo4j.driver.internal.connector.socket.SocketConnection.receiveOne(SocketConnection.java:143)
Stack trace truncated. Please see Cloud Logging for the entire trace.

Answer 1

死锁是＆＃34;正常＆＃34;的结果。存在并发请求时的neo4j行为。你应该知道neo4j的default locking behavior和documentation on deadlocks。

这可能是最有用的段落：

经历频繁的死锁是并发写入的指示请求以无法执行的方式发生他们同时实现了预期的隔离和一致性。解决方案是确保发生并发更新合理的方式。例如，给定两个特定节点（A和B），以随机顺序添加或删除这两个节点的关系当有两个或每个事务将导致死锁同时执行此操作的更多事务。一个解决方案是制作确保更新始终以相同的顺序发生（首先是A然后是B）。另一种解决方案是确保每个线程/事务不会与其他节点或关系的任何冲突写入并发交易。这可以例如通过让a来实现单线程执行特定类型的所有更新。

是neo4j-jdbc驱动3.x线程安全

1 个答案: