[jira] Commented: (NUTCH-835) document deduplication (exact duplicates) failed using MD5Signature
[ https://issues.apache.org/jira/browse/NUTCH-835?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=12884624#action_12884624 ] Julien Nioche commented on NUTCH-835: - This patch has been marked for 1.2 but has been committed to trunk only (2.0). Shall we also apply it to /nutch/branches/branch-1.2 ? document deduplication (exact duplicates) failed using MD5Signature --- Key: NUTCH-835 URL: https://issues.apache.org/jira/browse/NUTCH-835 Project: Nutch Issue Type: Bug Affects Versions: 1.0.0, 1.1 Environment: Linux, Ubuntu 10.04, Java 1.6.0_20 Reporter: Sebastian Nagel Assignee: Andrzej Bialecki Fix For: 1.2, 2.0 The MD5Signature class calculates different signatures for identical documents. The reason is that byte[] data = content.getContent(); ... StringBuilder().append(data) ... uses java.lang.Object.toString() to get a string representation of the (binary) content which results in unique hash codes (e.g., [...@30dc9065) even for two byte arrays with identical content. A solution would be to take the MD5 sum of the binary content as first part of the final signature calculation (the parsed content is the second part): ... .append(StringUtil.toHexString(MD5Hash.digest(data).getDigest())).append(parse.getText()); Of course, there are many other solutions... -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.
[jira] Commented: (NUTCH-835) document deduplication (exact duplicates) failed using MD5Signature
[ https://issues.apache.org/jira/browse/NUTCH-835?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=12884540#action_12884540 ] Hudson commented on NUTCH-835: -- Integrated in Nutch-trunk #1195 (See [http://hudson.zones.apache.org/hudson/job/Nutch-trunk/1195/]) NUTCH-835 Document deduplication failed using MD5Signature (Sebastian Nagel via ab) document deduplication (exact duplicates) failed using MD5Signature --- Key: NUTCH-835 URL: https://issues.apache.org/jira/browse/NUTCH-835 Project: Nutch Issue Type: Bug Affects Versions: 1.0.0, 1.1 Environment: Linux, Ubuntu 10.04, Java 1.6.0_20 Reporter: Sebastian Nagel Assignee: Andrzej Bialecki Fix For: 1.2, 2.0 The MD5Signature class calculates different signatures for identical documents. The reason is that byte[] data = content.getContent(); ... StringBuilder().append(data) ... uses java.lang.Object.toString() to get a string representation of the (binary) content which results in unique hash codes (e.g., [...@30dc9065) even for two byte arrays with identical content. A solution would be to take the MD5 sum of the binary content as first part of the final signature calculation (the parsed content is the second part): ... .append(StringUtil.toHexString(MD5Hash.digest(data).getDigest())).append(parse.getText()); Of course, there are many other solutions... -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.
