Github user shivzone commented on a diff in the pull request: https://github.com/apache/incubator-hawq/pull/1379#discussion_r199541316 --- Diff: pxf/pxf-service/src/main/java/org/apache/hawq/pxf/service/servlet/SecurityServletFilter.java --- @@ -42,8 +52,51 @@ private static final Log LOG = LogFactory.getLog(SecurityServletFilter.class); private static final String USER_HEADER = "X-GP-USER"; - private static final String MISSING_HEADER_ERROR = String.format("Header %s is missing in the request", USER_HEADER); - private static final String EMPTY_HEADER_ERROR = String.format("Header %s is empty in the request", USER_HEADER); + private static final String SEGMENT_INDEX_HEADER = "X-GP-SEGMENT-ID"; + private static final String TRANSACTION_ID_HEADER = "X-GP-XID"; + private static final String MISSING_HEADER_ERROR = "Header %s is missing in the request"; + private static final String EMPTY_HEADER_ERROR = "Header %s is empty in the request"; + private static Map<SegmentTransactionId, TimedProxyUGI> cache = new ConcurrentHashMap<>(); --- End diff -- Why not use apache commons JCS or guava's caching library as opposed to implementing it ourselves with timer ?
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