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1 | 1 | package io.dgraph.example;
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2 | 2 |
|
3 |
| -import io.dgraph.DgraphProto.Mutation; |
4 |
| -import io.dgraph.DgraphProto.Request; |
5 | 3 | import com.google.gson.Gson;
|
6 |
| -import io.dgraph.DgraphProto.Response; |
7 | 4 | import com.google.protobuf.ByteString;
|
8 | 5 | import io.dgraph.DgraphClient;
|
| 6 | +import io.dgraph.DgraphProto.Mutation; |
| 7 | +import io.dgraph.DgraphProto.Request; |
| 8 | +import io.dgraph.DgraphProto.Response; |
9 | 9 | import io.dgraph.Transaction;
|
10 | 10 | import io.dgraph.TxnConflictException;
|
11 | 11 | import java.util.Collections;
|
12 | 12 | import java.util.Map;
|
13 | 13 |
|
14 | 14 | public class MultiThreadedMutation implements Runnable {
|
15 |
| - // maximum retries |
16 |
| - static final int MAX_RETRY_COUNT = 5; |
17 |
| - static Integer globalThreadNumberCount = 1; |
18 |
| - int threadNumber = 0; |
19 |
| - // |
20 |
| - private DgraphClient dgraphClient; |
21 |
| - private Transaction txn; |
22 |
| - |
23 |
| - public MultiThreadedMutation(DgraphClient dgraphClient) { |
24 |
| - //assign a thread number |
25 |
| - synchronized (globalThreadNumberCount) { |
26 |
| - this.threadNumber = globalThreadNumberCount++; |
27 |
| - this.dgraphClient = dgraphClient; |
28 |
| - } |
29 |
| - |
30 |
| - } |
| 15 | + // maximum retries |
| 16 | + static final int MAX_RETRY_COUNT = 5; |
| 17 | + static Integer globalThreadNumberCount = 1; |
| 18 | + int threadNumber = 0; |
| 19 | + // |
| 20 | + private DgraphClient dgraphClient; |
| 21 | + private Transaction txn; |
31 | 22 |
|
32 |
| - public void run() { |
33 |
| - boolean successFlag = false; |
34 |
| - int retryCount = 0; |
35 |
| - while (retryCount < MAX_RETRY_COUNT) { |
36 |
| - try { |
37 |
| - //fire the mutation and check for exceptions |
38 |
| - doMutation(); |
39 |
| - successFlag = true; |
40 |
| - System.out.println(System.currentTimeMillis() + " Thread #" + threadNumber + " succeeded after " |
41 |
| - + retryCount + " retries"); |
42 |
| - break; |
43 |
| - } catch (TxnConflictException txnConflictException) { |
44 |
| - try { |
45 |
| - System.out.println(System.currentTimeMillis() + " Thread #" + threadNumber |
46 |
| - + " found a concurrent modification conflict, sleeping for 1 second..."); |
47 |
| - Thread.sleep(1000); |
48 |
| - System.out.println(System.currentTimeMillis() + " Thread #" + threadNumber + " resuming"); |
49 |
| - } catch (InterruptedException e) { |
50 |
| - e.printStackTrace(); |
51 |
| - } |
52 |
| - retryCount++; |
53 |
| - } catch (Exception e) { |
54 |
| - // cannot retry |
55 |
| - e.printStackTrace(); |
56 |
| - break; |
57 |
| - } |
58 |
| - } |
59 |
| - //check if maximum retries has been crossed |
60 |
| - if (!successFlag && retryCount >= MAX_RETRY_COUNT) { |
61 |
| - System.out.println(System.currentTimeMillis() + " Thread #" + threadNumber + " giving up transaction after " |
62 |
| - + (retryCount - 1) + " retries"); |
63 |
| - } |
64 |
| - } |
| 23 | + public MultiThreadedMutation(DgraphClient dgraphClient) { |
| 24 | + // assign a thread number |
| 25 | + synchronized (globalThreadNumberCount) { |
| 26 | + this.threadNumber = globalThreadNumberCount++; |
| 27 | + this.dgraphClient = dgraphClient; |
| 28 | + } |
| 29 | + } |
65 | 30 |
|
66 |
| - private void doMutation() throws Exception { |
67 |
| - txn = dgraphClient.newTransaction(); |
68 |
| - Gson gson = new Gson(); |
69 |
| - // Query |
70 |
| - String query = "query all($a: string){\n" + " all(func: eq(name, $a)) {\n" + " " + "uid\n" + "name\n" |
71 |
| - + "clickCount\n" + " }\n" + "}\n"; |
| 31 | + public void run() { |
| 32 | + boolean successFlag = false; |
| 33 | + int retryCount = 0; |
| 34 | + while (retryCount < MAX_RETRY_COUNT) { |
| 35 | + try { |
| 36 | + // fire the mutation and check for exceptions |
| 37 | + doMutation(); |
| 38 | + successFlag = true; |
| 39 | + System.out.println( |
| 40 | + System.currentTimeMillis() |
| 41 | + + " Thread #" |
| 42 | + + threadNumber |
| 43 | + + " succeeded after " |
| 44 | + + retryCount |
| 45 | + + " retries"); |
| 46 | + break; |
| 47 | + } catch (TxnConflictException txnConflictException) { |
| 48 | + try { |
| 49 | + System.out.println( |
| 50 | + System.currentTimeMillis() |
| 51 | + + " Thread #" |
| 52 | + + threadNumber |
| 53 | + + " found a concurrent modification conflict, sleeping for 1 second..."); |
| 54 | + Thread.sleep(1000); |
| 55 | + System.out.println(System.currentTimeMillis() + " Thread #" + threadNumber + " resuming"); |
| 56 | + } catch (InterruptedException e) { |
| 57 | + e.printStackTrace(); |
| 58 | + } |
| 59 | + retryCount++; |
| 60 | + } catch (Exception e) { |
| 61 | + // cannot retry |
| 62 | + e.printStackTrace(); |
| 63 | + break; |
| 64 | + } |
| 65 | + } |
| 66 | + // check if maximum retries has been crossed |
| 67 | + if (!successFlag && retryCount >= MAX_RETRY_COUNT) { |
| 68 | + System.out.println( |
| 69 | + System.currentTimeMillis() |
| 70 | + + " Thread #" |
| 71 | + + threadNumber |
| 72 | + + " giving up transaction after " |
| 73 | + + (retryCount - 1) |
| 74 | + + " retries"); |
| 75 | + } |
| 76 | + } |
72 | 77 |
|
73 |
| - Map<String, String> vars = Collections.singletonMap("$a", "Alice"); |
| 78 | + private void doMutation() throws Exception { |
| 79 | + txn = dgraphClient.newTransaction(); |
| 80 | + Gson gson = new Gson(); |
| 81 | + // Query |
| 82 | + String query = |
| 83 | + "query all($a: string){\n" |
| 84 | + + " all(func: eq(name, $a)) {\n" |
| 85 | + + " " |
| 86 | + + "uid\n" |
| 87 | + + "name\n" |
| 88 | + + "clickCount\n" |
| 89 | + + " }\n" |
| 90 | + + "}\n"; |
74 | 91 |
|
75 |
| - Response response = dgraphClient.newReadOnlyTransaction().queryWithVars(query, vars); |
76 |
| - People ppl = gson.fromJson(response.getJson().toStringUtf8(), People.class); |
77 |
| - // |
78 |
| - for (Person person : ppl.all) { |
79 |
| - System.out.println(System.currentTimeMillis() + " Thread #" + threadNumber |
80 |
| - + " increasing clickCount for uid " + person.uid + ", Name: " + person.name); |
81 |
| - //increment clickCount |
82 |
| - person.clickCount = person.clickCount + 1; |
| 92 | + Map<String, String> vars = Collections.singletonMap("$a", "Alice"); |
83 | 93 |
|
84 |
| - try { |
85 |
| - //find and update alice's clickCount in a transaction |
86 |
| - String upsertQuery = "query {\n" + "user as var(func: eq(name, \"" + person.name + "\"))\n" + "}\n"; |
87 |
| - Mutation mu2 = Mutation.newBuilder() |
88 |
| - .setSetNquads(ByteString.copyFromUtf8("uid(user) <clickCount> \"" + person.clickCount + "\" .")) |
89 |
| - .build(); |
| 94 | + Response response = dgraphClient.newReadOnlyTransaction().queryWithVars(query, vars); |
| 95 | + People ppl = gson.fromJson(response.getJson().toStringUtf8(), People.class); |
| 96 | + // |
| 97 | + for (Person person : ppl.all) { |
| 98 | + System.out.println( |
| 99 | + System.currentTimeMillis() |
| 100 | + + " Thread #" |
| 101 | + + threadNumber |
| 102 | + + " increasing clickCount for uid " |
| 103 | + + person.uid |
| 104 | + + ", Name: " |
| 105 | + + person.name); |
| 106 | + // increment clickCount |
| 107 | + person.clickCount = person.clickCount + 1; |
90 | 108 |
|
91 |
| - Request request = Request.newBuilder().setQuery(upsertQuery).addMutations(mu2).setCommitNow(true) |
92 |
| - .build(); |
93 |
| - txn.doRequest(request); |
94 |
| - txn.close(); |
95 |
| - } catch (Exception ex) { |
96 |
| - // if its a conflict exception, we can retry |
97 |
| - if (ex.getCause().getCause() instanceof TxnConflictException) { |
98 |
| - TxnConflictException txnConflictException = (TxnConflictException) ex.getCause().getCause(); |
99 |
| - txn.close(); |
100 |
| - throw (txnConflictException); |
101 |
| - } else { |
102 |
| - throw ex; |
103 |
| - } |
| 109 | + try { |
| 110 | + // find and update alice's clickCount in a transaction |
| 111 | + String upsertQuery = |
| 112 | + "query {\n" + "user as var(func: eq(name, \"" + person.name + "\"))\n" + "}\n"; |
| 113 | + Mutation mu2 = |
| 114 | + Mutation.newBuilder() |
| 115 | + .setSetNquads( |
| 116 | + ByteString.copyFromUtf8( |
| 117 | + "uid(user) <clickCount> \"" + person.clickCount + "\" .")) |
| 118 | + .build(); |
104 | 119 |
|
105 |
| - } finally { |
106 |
| - txn.discard(); |
107 |
| - } |
| 120 | + Request request = |
| 121 | + Request.newBuilder().setQuery(upsertQuery).addMutations(mu2).setCommitNow(true).build(); |
| 122 | + txn.doRequest(request); |
| 123 | + txn.close(); |
| 124 | + } catch (Exception ex) { |
| 125 | + // if its a conflict exception, we can retry |
| 126 | + if (ex.getCause().getCause() instanceof TxnConflictException) { |
| 127 | + TxnConflictException txnConflictException = |
| 128 | + (TxnConflictException) ex.getCause().getCause(); |
| 129 | + txn.close(); |
| 130 | + throw (txnConflictException); |
| 131 | + } else { |
| 132 | + throw ex; |
| 133 | + } |
108 | 134 |
|
109 |
| - } |
110 |
| - } |
| 135 | + } finally { |
| 136 | + txn.discard(); |
| 137 | + } |
| 138 | + } |
| 139 | + } |
111 | 140 | }
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