1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
package org.onap.music.datastore;
import java.util.List;
import java.util.UUID;
import org.onap.music.eelf.logging.EELFLoggerDelegate;
import org.onap.music.exceptions.MusicQueryException;
import org.onap.music.exceptions.MusicServiceException;
import org.onap.music.main.MusicUtil;
import com.datastax.driver.core.ResultSet;
import com.datastax.driver.core.Row;
import com.datastax.driver.core.utils.UUIDs;
/*
* This is the lock store that is built on top of Cassandra that is used by MUSIC to maintain lock state.
*/
public class CassaLockStore {
private EELFLoggerDelegate logger = EELFLoggerDelegate.getLogger(CassaLockStore.class);
public class LockObject{
public String lockRef;
public String createTime;
public String acquireTime;
public LockObject(String lockRef, String createTime, String acquireTime) {
this.lockRef = lockRef;
this.acquireTime = acquireTime;
this.createTime = createTime;
}
}
CassaDataStore dsHandle;
public CassaLockStore() {
dsHandle = new CassaDataStore();
}
public CassaLockStore(CassaDataStore dsHandle) {
this.dsHandle=dsHandle;
}
/**
*
* This method creates a shadow locking table for every main table in Cassandra. This table tracks all information regarding locks.
* @param keyspace of the application.
* @param table of the application.
* @return true if the operation was successful.
* @throws MusicServiceException
* @throws MusicQueryException
*/
public boolean createLockQueue(String keyspace, String table) throws MusicServiceException, MusicQueryException {
logger.info(EELFLoggerDelegate.applicationLogger,
"Create lock queue/table for " + keyspace+"."+table);
table = "lockQ_"+table;
String tabQuery = "CREATE TABLE IF NOT EXISTS "+keyspace+"."+table
+ " ( key text, lockReference bigint, createTime text, acquireTime text, guard bigint static, PRIMARY KEY ((key), lockReference) ) "
+ "WITH CLUSTERING ORDER BY (lockReference ASC);";
System.out.println(tabQuery);
PreparedQueryObject queryObject = new PreparedQueryObject();
queryObject.appendQueryString(tabQuery);
boolean result;
result = dsHandle.executePut(queryObject, "eventual");
return result;
}
/**
* This method creates a lock reference for each invocation. The lock references are monotonically increasing timestamps.
* @param keyspace of the locks.
* @param table of the locks.
* @param lockName is the primary key of the lock table
* @return the UUID lock reference.
* @throws MusicServiceException
* @throws MusicQueryException
*/
public String genLockRefandEnQueue(String keyspace, String table, String lockName) throws MusicServiceException, MusicQueryException {
logger.info(EELFLoggerDelegate.applicationLogger,
"Create lock reference for " + keyspace + "." + table + "." + lockName);
table = "lockQ_" + table;
PreparedQueryObject queryObject = new PreparedQueryObject();
String selectQuery = "SELECT guard FROM " + keyspace + "." + table + " WHERE key=?;";
queryObject.addValue(lockName);
queryObject.appendQueryString(selectQuery);
ResultSet gqResult = dsHandle.executeEventualGet(queryObject);
List<Row> latestGuardRow = gqResult.all();
long prevGuard = 0;
long lockRef = 1;
if (latestGuardRow.size() > 0) {
prevGuard = latestGuardRow.get(0).getLong(0);
lockRef = prevGuard + 1;
}
long lockEpochMillis = System.currentTimeMillis();
// System.out.println("guard(" + lockName + "): " + prevGuard + "->" + lockRef);
logger.info(EELFLoggerDelegate.applicationLogger,
"Created lock reference for " + keyspace + "." + table + "." + lockName + ":" + lockRef);
queryObject = new PreparedQueryObject();
String insQuery = "BEGIN BATCH" +
" UPDATE " + keyspace + "." + table +
" SET guard=? WHERE key=? IF guard = " + (prevGuard == 0 ? "NULL" : "?") +";" +
" INSERT INTO " + keyspace + "." + table +
"(key, lockReference, createTime, acquireTime) VALUES (?,?,?,?) IF NOT EXISTS; APPLY BATCH;";
queryObject.addValue(lockRef);
queryObject.addValue(lockName);
if (prevGuard != 0)
queryObject.addValue(prevGuard);
queryObject.addValue(lockName);
queryObject.addValue(lockRef);
queryObject.addValue(String.valueOf(lockEpochMillis));
queryObject.addValue("0");
queryObject.appendQueryString(insQuery);
boolean pResult = dsHandle.executePut(queryObject, "critical");
return String.valueOf(lockRef);
}
/**
* This method returns the top of lock table/queue for the key.
* @param keyspace of the application.
* @param table of the application.
* @param key is the primary key of the application table
* @return the UUID lock reference.
* @throws MusicServiceException
* @throws MusicQueryException
*/
public LockObject peekLockQueue(String keyspace, String table, String key) throws MusicServiceException, MusicQueryException{
logger.info(EELFLoggerDelegate.applicationLogger,
"Peek in lock table for " + keyspace+"."+table+"."+key);
table = "lockQ_"+table;
String selectQuery = "select * from "+keyspace+"."+table+" where key='"+key+"' LIMIT 1;";
PreparedQueryObject queryObject = new PreparedQueryObject();
queryObject.appendQueryString(selectQuery);
ResultSet results = dsHandle.executeEventualGet(queryObject);
Row row = results.one();
String lockReference = "" + row.getLong("lockReference");
String createTime = row.getString("createTime");
String acquireTime = row.getString("acquireTime");
return new LockObject(lockReference, createTime,acquireTime);
}
/**
* This method removes the lock ref from the lock table/queue for the key.
* @param keyspace of the application.
* @param table of the application.
* @param key is the primary key of the application table
* @param lockReference the lock reference that needs to be dequeued.
* @throws MusicServiceException
* @throws MusicQueryException
*/
public void deQueueLockRef(String keyspace, String table, String key, String lockReference) throws MusicServiceException, MusicQueryException{
table = "lockQ_"+table;
PreparedQueryObject queryObject = new PreparedQueryObject();
Long lockReferenceL = Long.parseLong(lockReference);
String deleteQuery = "delete from "+keyspace+"."+table+" where key='"+key+"' AND lockReference ="+lockReferenceL+" IF EXISTS;";
queryObject.appendQueryString(deleteQuery);
dsHandle.executePut(queryObject, "critical");
}
public void updateLockAcquireTime(String keyspace, String table, String key, String lockReference) throws MusicServiceException, MusicQueryException{
table = "lockQ_"+table;
PreparedQueryObject queryObject = new PreparedQueryObject();
Long lockReferenceL = Long.parseLong(lockReference);
String updateQuery = "update "+keyspace+"."+table+" set acquireTime='"+ System.currentTimeMillis()+"' where key='"+key+"' AND lockReference = "+lockReferenceL+" IF EXISTS;";
queryObject.appendQueryString(updateQuery);
dsHandle.executePut(queryObject, "eventual");
}
}
|
