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Flavio Junqueira commented on ZOOKEEPER-1622: --------------------------------------------- [~phunt], is this a +1 for you? > session ids will be negative in the year 2022 > --------------------------------------------- > > Key: ZOOKEEPER-1622 > URL: https://issues.apache.org/jira/browse/ZOOKEEPER-1622 > Project: ZooKeeper > Issue Type: Bug > Affects Versions: 3.4.0, 3.5.0 > Reporter: Eric Newton > Assignee: Eric Newton > Priority: Trivial > Fix For: 3.4.6, 3.5.0 > > Attachments: ZOOKEEPER-1622.patch > > > Someone decided to use a large number for their myid file. This cause > session ids to go negative, and our software (Apache Accumulo) did not handle > this very well. While diagnosing the problem, I noticed this in SessionImpl: > {noformat} > public static long initializeNextSession(long id) { > long nextSid = 0; > nextSid = (System.currentTimeMillis() << 24) >> 8; > nextSid = nextSid | (id <<56); > return nextSid; > } > {noformat} > When the 40th bit in System.currentTimeMillis() is a one, sign extension will > fill the upper 8 bytes of nextSid, and id will not make the session id > unique. I recommend changing the right shift to the logical shift: > {noformat} > public static long initializeNextSession(long id) { > long nextSid = 0; > nextSid = (System.currentTimeMillis() << 24) >>> 8; > nextSid = nextSid | (id <<56); > return nextSid; > } > {noformat} > But, we have until the year 2022 before we have to worry about it. -- This message was sent by Atlassian JIRA (v6.1#6144)