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The following commit(s) were added to refs/heads/asf-site by this push:
new 103c1db Jekyll build from gh-pages:8590b7a
103c1db is described below
commit 103c1db6facbbf7fae1d7af616cdf3afefdc9979
Author: Keith Turner <[email protected]>
AuthorDate: Wed Mar 28 10:31:15 2018 -0400
Jekyll build from gh-pages:8590b7a
Added read locks to tour (#156)
---
feed.xml | 4 +-
tour/application-configuration/index.html | 4 +-
tour/architecture/index.html | 4 +-
tour/basic-read-write/index.html | 4 +-
tour/collision-code/index.html | 4 +-
tour/collisions/index.html | 4 +-
tour/data-model/index.html | 4 +-
tour/data-pojos/index.html | 4 +-
tour/exercise-1/index.html | 4 +-
tour/index.html | 6 +
tour/loader-executer/index.html | 4 +-
tour/mem-self-ntfy-code/index.html | 4 +-
tour/mem-self-ntfy/index.html | 4 +-
tour/multi-get/index.html | 4 +-
tour/observer_example/index.html | 4 +-
tour/observers/index.html | 4 +-
.../index.html | 122 +++++++++------------
tour/{write-skew => read-lock}/index.html | 52 +++++----
tour/recipes/index.html | 4 +-
tour/row-locking/index.html | 4 +-
tour/scanning-code/index.html | 4 +-
tour/scanning/index.html | 8 +-
tour/snapshot-isolation-code/index.html | 4 +-
tour/snapshot-isolation/index.html | 4 +-
tour/tx-logging/index.html | 4 +-
tour/weak-code/index.html | 4 +-
tour/weak-notifications/index.html | 4 +-
tour/write-skew-code/index.html | 8 +-
tour/write-skew/index.html | 7 +-
tour/writing-code/index.html | 4 +-
30 files changed, 142 insertions(+), 157 deletions(-)
diff --git a/feed.xml b/feed.xml
index e42ccf5..8a4ac27 100644
--- a/feed.xml
+++ b/feed.xml
@@ -5,8 +5,8 @@
<description>Apache Fluo Website</description>
<link>https://fluo.apache.org//</link>
<atom:link href="https://fluo.apache.org//feed.xml"; rel="self"
type="application/rss+xml" />
- <pubDate>Fri, 23 Mar 2018 21:37:01 +0000</pubDate>
- <lastBuildDate>Fri, 23 Mar 2018 21:37:01 +0000</lastBuildDate>
+ <pubDate>Wed, 28 Mar 2018 14:31:09 +0000</pubDate>
+ <lastBuildDate>Wed, 28 Mar 2018 14:31:09 +0000</lastBuildDate>
<generator>Jekyll v3.6.2</generator>
diff --git a/tour/application-configuration/index.html
b/tour/application-configuration/index.html
index a1b3811..9f8a940 100644
--- a/tour/application-configuration/index.html
+++ b/tour/application-configuration/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Application Configuration</h2>
- <p class="text-muted">Tour page 23 of 26</p>
+ <p class="text-muted">Tour page 25 of 28</p>
</div>
<div id="tour-content">
<p>Fluo applications are distributed applications where code is running on
many separate machines.
@@ -261,7 +261,7 @@ if (e.keyCode == '39') { window.location =
'/tour/mem-self-ntfy/'; }
<a href="/tour/weak-code/"><</a>
- 23 / 26
+ 25 / 28
<a href="/tour/mem-self-ntfy/">></a>
diff --git a/tour/architecture/index.html b/tour/architecture/index.html
index 1a9a84a..d25a362 100644
--- a/tour/architecture/index.html
+++ b/tour/architecture/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Architecture</h2>
- <p class="text-muted">Tour page 2 of 26</p>
+ <p class="text-muted">Tour page 2 of 28</p>
</div>
<div id="tour-content">
<p>An <a href="/docs/fluo/1.2/getting-started/design">overview</a> of the
Fluo Architecture can be found in Fluo’s documentation.</p>
@@ -139,7 +139,7 @@ if (e.keyCode == '39') { window.location =
'/tour/writing-code/'; }
<a href="/tour/data-model/"><</a>
- 2 / 26
+ 2 / 28
<a href="/tour/writing-code/">></a>
diff --git a/tour/basic-read-write/index.html b/tour/basic-read-write/index.html
index 28317fc..69accfa 100644
--- a/tour/basic-read-write/index.html
+++ b/tour/basic-read-write/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Read and Write Data</h2>
- <p class="text-muted">Tour page 4 of 26</p>
+ <p class="text-muted">Tour page 4 of 28</p>
</div>
<div id="tour-content">
<p>The following shows Java code for writing and reading data using Fluo.
In your local clone, modify
@@ -172,7 +172,7 @@ if (e.keyCode == '39') { window.location =
'/tour/data-pojos/'; }
<a href="/tour/writing-code/"><</a>
- 4 / 26
+ 4 / 28
<a href="/tour/data-pojos/">></a>
diff --git a/tour/collision-code/index.html b/tour/collision-code/index.html
index a80db9c..44998ab 100644
--- a/tour/collision-code/index.html
+++ b/tour/collision-code/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Collision code</h2>
- <p class="text-muted">Tour page 9 of 26</p>
+ <p class="text-muted">Tour page 9 of 28</p>
</div>
<div id="tour-content">
<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code> <span class="kd">private</span> <span
class="kd">static</span> <span class="kt">void</span> <span
class="nf">exercise</span><span class="o">(</span><span
class="n">MiniFluo</span> <span class="n">mini</span><span class="o">,</span>
<span class="n">FluoClient</span> <span class="n">client</span><span
class="o">)</span> <span class="o">{</span>
@@ -172,7 +172,7 @@ if (e.keyCode == '39') { window.location =
'/tour/tx-logging/'; }
<a href="/tour/collisions/"><</a>
- 9 / 26
+ 9 / 28
<a href="/tour/tx-logging/">></a>
diff --git a/tour/collisions/index.html b/tour/collisions/index.html
index 58e50a7..396b636 100644
--- a/tour/collisions/index.html
+++ b/tour/collisions/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Collisions</h2>
- <p class="text-muted">Tour page 8 of 26</p>
+ <p class="text-muted">Tour page 8 of 28</p>
</div>
<div id="tour-content">
<p>When two transactions overlap and attempt to modify the same data, one of
them
@@ -152,7 +152,7 @@ if (e.keyCode == '39') { window.location =
'/tour/collision-code/'; }
<a href="/tour/snapshot-isolation-code/"><</a>
- 8 / 26
+ 8 / 28
<a href="/tour/collision-code/">></a>
diff --git a/tour/data-model/index.html b/tour/data-model/index.html
index a353594..311f6f8 100644
--- a/tour/data-model/index.html
+++ b/tour/data-model/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Data Model</h2>
- <p class="text-muted">Tour page 1 of 26</p>
+ <p class="text-muted">Tour page 1 of 28</p>
</div>
<div id="tour-content">
<p>Fluo uses Accumulo’s data model which is based on the BigTable data model.
@@ -167,7 +167,7 @@ if (e.keyCode == '39') { window.location =
'/tour/architecture/'; }
<h2>
- 1 / 26
+ 1 / 28
<a href="/tour/architecture/">></a>
diff --git a/tour/data-pojos/index.html b/tour/data-pojos/index.html
index 5a31058..1d2cb50 100644
--- a/tour/data-pojos/index.html
+++ b/tour/data-pojos/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Basic Data Types</h2>
- <p class="text-muted">Tour page 5 of 26</p>
+ <p class="text-muted">Tour page 5 of 28</p>
</div>
<div id="tour-content">
<p>Fluo has a few simple POJOs that are used throughout the API. These
classes
@@ -149,7 +149,7 @@ if (e.keyCode == '39') { window.location =
'/tour/snapshot-isolation/'; }
<a href="/tour/basic-read-write/"><</a>
- 5 / 26
+ 5 / 28
<a href="/tour/snapshot-isolation/">></a>
diff --git a/tour/exercise-1/index.html b/tour/exercise-1/index.html
index b9f34dc..3fb6b80 100644
--- a/tour/exercise-1/index.html
+++ b/tour/exercise-1/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Word counts for unique documents
exercise</h2>
- <p class="text-muted">Tour page 19 of 26</p>
+ <p class="text-muted">Tour page 21 of 28</p>
</div>
<div id="tour-content">
<p>This exercise gives you an opportunity to use everything you have learned
so
@@ -754,7 +754,7 @@ if (e.keyCode == '39') { window.location =
'/tour/row-locking/'; }
<a href="/tour/observer_example/"><</a>
- 19 / 26
+ 21 / 28
<a href="/tour/row-locking/">></a>
diff --git a/tour/index.html b/tour/index.html
index 86689a8..603d838 100644
--- a/tour/index.html
+++ b/tour/index.html
@@ -174,6 +174,12 @@ thoughts, solutions, etc related to this tour can also be
tweeted using the has
<p><a href="/tour/write-skew-code/">Write Skew Code</a></p>
</li>
<li>
+ <p><a href="/tour/read-lock/">Read Locks</a></p>
+ </li>
+ <li>
+ <p><a href="/tour/read-lock-code/">Read Lock Code</a></p>
+ </li>
+ <li>
<p><a href="/tour/scanning/">Scanning</a></p>
</li>
<li>
diff --git a/tour/loader-executer/index.html b/tour/loader-executer/index.html
index 0e512d9..eff2258 100644
--- a/tour/loader-executer/index.html
+++ b/tour/loader-executer/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Loader Executor</h2>
- <p class="text-muted">Tour page 16 of 26</p>
+ <p class="text-muted">Tour page 18 of 28</p>
</div>
<div id="tour-content">
<p>Fluo provides a simple mechanism to help load data called the <a
href="https://javadoc.io/page/org.apache.fluo/fluo-api/1.2.0/org/apache/fluo/api/client/LoaderExecutor.html";>LoaderExecutor</a>.
Loading data
@@ -152,7 +152,7 @@ if (e.keyCode == '39') { window.location =
'/tour/observers/'; }
<a href="/tour/multi-get/"><</a>
- 16 / 26
+ 18 / 28
<a href="/tour/observers/">></a>
diff --git a/tour/mem-self-ntfy-code/index.html
b/tour/mem-self-ntfy-code/index.html
index dc5790d..f06b581 100644
--- a/tour/mem-self-ntfy-code/index.html
+++ b/tour/mem-self-ntfy-code/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Memory limits and self notify code</h2>
- <p class="text-muted">Tour page 25 of 26</p>
+ <p class="text-muted">Tour page 27 of 28</p>
</div>
<div id="tour-content">
<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code> <span class="kd">static</span> <span
class="n">Column</span> <span class="n">NC</span> <span class="o">=</span>
<span class="k">new</span> <span class="n">Column</span><span
class="o">(</span><span class="s">"ntyf"</span><span class="o">,</span> <span
class="s">"sum"</span><span class="o">);</span>
@@ -247,7 +247,7 @@ if (e.keyCode == '39') { window.location =
'/tour/recipes/'; }
<a href="/tour/mem-self-ntfy/"><</a>
- 25 / 26
+ 27 / 28
<a href="/tour/recipes/">></a>
diff --git a/tour/mem-self-ntfy/index.html b/tour/mem-self-ntfy/index.html
index 9d2ac16..777e0af 100644
--- a/tour/mem-self-ntfy/index.html
+++ b/tour/mem-self-ntfy/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Memory limits and self notify</h2>
- <p class="text-muted">Tour page 24 of 26</p>
+ <p class="text-muted">Tour page 26 of 28</p>
</div>
<div id="tour-content">
<p>All modifications made as part of a transaction must fit into memory
because the sets and deletes
@@ -157,7 +157,7 @@ if (e.keyCode == '39') { window.location =
'/tour/mem-self-ntfy-code/'; }
<a href="/tour/application-configuration/"><</a>
- 24 / 26
+ 26 / 28
<a href="/tour/mem-self-ntfy-code/">></a>
diff --git a/tour/multi-get/index.html b/tour/multi-get/index.html
index 73fca5d..b275205 100644
--- a/tour/multi-get/index.html
+++ b/tour/multi-get/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Fetching multiple cells</h2>
- <p class="text-muted">Tour page 15 of 26</p>
+ <p class="text-muted">Tour page 17 of 28</p>
</div>
<div id="tour-content">
<p>Each call to get a row column results in a RPC to an Accumulo server. In
the cases where there are
@@ -268,7 +268,7 @@ if (e.keyCode == '39') { window.location =
'/tour/loader-executer/'; }
<a href="/tour/scanning-code/"><</a>
- 15 / 26
+ 17 / 28
<a href="/tour/loader-executer/">></a>
diff --git a/tour/observer_example/index.html b/tour/observer_example/index.html
index 7649453..47d64f4 100644
--- a/tour/observer_example/index.html
+++ b/tour/observer_example/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Observer Example</h2>
- <p class="text-muted">Tour page 18 of 26</p>
+ <p class="text-muted">Tour page 20 of 28</p>
</div>
<div id="tour-content">
<p>The following code shows how to setup and trigger an observer. The
observer is triggered when the
@@ -217,7 +217,7 @@ if (e.keyCode == '39') { window.location =
'/tour/exercise-1/'; }
<a href="/tour/observers/"><</a>
- 18 / 26
+ 20 / 28
<a href="/tour/exercise-1/">></a>
diff --git a/tour/observers/index.html b/tour/observers/index.html
index cbc4e49..98edad3 100644
--- a/tour/observers/index.html
+++ b/tour/observers/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Observer Concepts</h2>
- <p class="text-muted">Tour page 17 of 26</p>
+ <p class="text-muted">Tour page 19 of 28</p>
</div>
<div id="tour-content">
<p>Fluo supports incremental processing with Observers and Notifications.
Notifications are persistent
@@ -160,7 +160,7 @@ if (e.keyCode == '39') { window.location =
'/tour/observer_example/'; }
<a href="/tour/loader-executer/"><</a>
- 17 / 26
+ 19 / 28
<a href="/tour/observer_example/">></a>
diff --git a/tour/observer_example/index.html b/tour/read-lock-code/index.html
similarity index 51%
copy from tour/observer_example/index.html
copy to tour/read-lock-code/index.html
index 7649453..d27e3de 100644
--- a/tour/observer_example/index.html
+++ b/tour/read-lock-code/index.html
@@ -8,10 +8,10 @@
<link
href="https://maxcdn.bootstrapcdn.com/bootswatch/3.3.7/cosmo/bootstrap.min.css";
rel="stylesheet"
integrity="sha384-h21C2fcDk/eFsW9sC9h0dhokq5pDinLNklTKoxIZRUn3+hvmgQSffLLQ4G4l2eEr"
crossorigin="anonymous">
<link
href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css";
rel="stylesheet"
integrity="sha384-wvfXpqpZZVQGK6TAh5PVlGOfQNHSoD2xbE+QkPxCAFlNEevoEH3Sl0sibVcOQVnN"
crossorigin="anonymous">
<link rel="stylesheet" href="/css/fluo.css">
- <link rel="canonical"
href="https://fluo.apache.org//tour/observer_example/";>
+ <link rel="canonical" href="https://fluo.apache.org//tour/read-lock-code/";>
<link rel="icon" type="image/png" href="/resources/favicon.png">
- <title>Observer Example | Apache Fluo</title>
+ <title>Read Lock Code | Apache Fluo</title>
<script
src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js";></script>
<script
src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js";
integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa"
crossorigin="anonymous"></script>
@@ -111,101 +111,81 @@
<div id="tour-header">
- <h2><a href="/tour/">Fluo Tour</a>: Observer Example</h2>
- <p class="text-muted">Tour page 18 of 26</p>
+ <h2><a href="/tour/">Fluo Tour</a>: Read Lock Code</h2>
+ <p class="text-muted">Tour page 14 of 28</p>
</div>
<div id="tour-content">
- <p>The following code shows how to setup and trigger an observer. The
observer is triggered when the
-column <em>obs:data</em> is changed.</p>
-
-<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code> <span class="kd">public</span> <span
class="kd">static</span> <span class="kd">final</span> <span
class="n">Column</span> <span class="n">OBSERVED_COL</span> <span
class="o">=</span> <span class="k">new</span> <span
class="n">Column</span><span class="o">(</span><span
class="s">"obs"</span><span class="o">,</span> <span
class="s">"data"</span><span class="o">);</span>
- <span class="kd">public</span> <span class="kd">static</span> <span
class="kd">final</span> <span class="n">Column</span> <span
class="n">INVERT_COL</span> <span class="o">=</span> <span class="k">new</span>
<span class="n">Column</span><span class="o">(</span><span
class="s">"inv"</span><span class="o">,</span> <span
class="s">"data"</span><span class="o">);</span>
-
- <span class="c1">// This class is responsible for registering Observers for
all observed columns.</span>
- <span class="kd">public</span> <span class="kd">static</span> <span
class="kd">class</span> <span class="nc">MyObserverProvider</span> <span
class="kd">implements</span> <span class="n">ObserverProvider</span> <span
class="o">{</span>
-
- <span class="nd">@Override</span>
- <span class="kd">public</span> <span class="kt">void</span> <span
class="nf">provide</span><span class="o">(</span><span
class="n">Registry</span> <span class="n">obsRegistry</span><span
class="o">,</span> <span class="n">Context</span> <span
class="n">ctx</span><span class="o">)</span> <span class="o">{</span>
-
- <span class="c1">// Observer is a functional interface allowing
Observers to be lambdas</span>
- <span class="n">Observer</span> <span class="n">invObserver</span> <span
class="o">=</span> <span class="o">(</span><span class="n">tx</span><span
class="o">,</span> <span class="n">row</span><span class="o">,</span> <span
class="n">col</span><span class="o">)</span> <span class="o">-></span> <span
class="o">{</span>
- <span class="n">Bytes</span> <span class="n">value</span> <span
class="o">=</span> <span class="n">tx</span><span class="o">.</span><span
class="na">get</span><span class="o">(</span><span class="n">row</span><span
class="o">,</span> <span class="n">col</span><span class="o">);</span>
- <span class="n">tx</span><span class="o">.</span><span
class="na">set</span><span class="o">(</span><span class="n">value</span><span
class="o">,</span> <span class="n">INVERT_COL</span><span class="o">,</span>
<span class="n">row</span><span class="o">);</span>
- <span class="o">};</span>
-
- <span class="c1">// Register an observer to process notifications for
the column obs:data</span>
- <span class="n">obsRegistry</span><span class="o">.</span><span
class="na">forColumn</span><span class="o">(</span><span
class="n">OBSERVED_COL</span><span class="o">,</span> <span
class="n">NotificationType</span><span class="o">.</span><span
class="na">STRONG</span><span class="o">).</span><span
class="na">useObserver</span><span class="o">(</span><span
class="n">invObserver</span><span class="o">);</span>
- <span class="o">}</span>
-
- <span class="o">}</span>
-
- <span class="kd">private</span> <span class="kd">static</span> <span
class="kt">void</span> <span class="nf">preInit</span><span
class="o">(</span><span class="n">FluoConfiguration</span> <span
class="n">fluoConfig</span><span class="o">)</span> <span class="o">{</span>
- <span class="c1">// Configure ObserverProvider before initialization.
Workers will instantiate this class and use</span>
- <span class="c1">// it to create Observers.</span>
- <span class="n">fluoConfig</span><span class="o">.</span><span
class="na">setObserverProvider</span><span class="o">(</span><span
class="n">MyObserverProvider</span><span class="o">.</span><span
class="na">class</span><span class="o">);</span>
- <span class="o">}</span>
+ <div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code> <span class="kd">private</span> <span
class="kd">static</span> <span class="kd">final</span> <span
class="n">Column</span> <span class="n">WEIGHT_COL</span> <span
class="o">=</span> <span class="k">new</span> <span
class="n">Column</span><span class="o">(</span><span
class="s">"stat"</span><span class="o">,</span> <span
class="s">"weight"</span><span class="o">);</span>
<span class="kd">private</span> <span class="kd">static</span> <span
class="kt">void</span> <span class="nf">exercise</span><span
class="o">(</span><span class="n">MiniFluo</span> <span
class="n">mini</span><span class="o">,</span> <span class="n">FluoClient</span>
<span class="n">client</span><span class="o">)</span> <span class="o">{</span>
<span class="k">try</span> <span class="o">(</span><span
class="n">Transaction</span> <span class="n">tx1</span> <span
class="o">=</span> <span class="n">client</span><span class="o">.</span><span
class="na">newTransaction</span><span class="o">())</span> <span
class="o">{</span>
- <span class="n">tx1</span><span class="o">.</span><span
class="na">set</span><span class="o">(</span><span
class="s">"kerbalnaut0001"</span><span class="o">,</span> <span
class="n">OBSERVED_COL</span><span class="o">,</span> <span
class="s">"Jebediah"</span><span class="o">);</span>
+ <span class="n">tx1</span><span class="o">.</span><span
class="na">set</span><span class="o">(</span><span
class="s">"kerbalnaut0001"</span><span class="o">,</span> <span
class="n">WEIGHT_COL</span><span class="o">,</span> <span
class="s">"90"</span><span class="o">);</span>
+ <span class="n">tx1</span><span class="o">.</span><span
class="na">set</span><span class="o">(</span><span
class="s">"kerbalnaut0002"</span><span class="o">,</span> <span
class="n">WEIGHT_COL</span><span class="o">,</span> <span
class="s">"70"</span><span class="o">);</span>
+ <span class="n">tx1</span><span class="o">.</span><span
class="na">set</span><span class="o">(</span><span
class="s">"kerbalnaut0003"</span><span class="o">,</span> <span
class="n">WEIGHT_COL</span><span class="o">,</span> <span
class="s">"80"</span><span class="o">);</span>
<span class="n">tx1</span><span class="o">.</span><span
class="na">commit</span><span class="o">();</span>
<span class="o">}</span>
- <span class="k">try</span> <span class="o">(</span><span
class="n">Transaction</span> <span class="n">tx2</span> <span
class="o">=</span> <span class="n">client</span><span class="o">.</span><span
class="na">newTransaction</span><span class="o">())</span> <span
class="o">{</span>
- <span class="n">tx2</span><span class="o">.</span><span
class="na">set</span><span class="o">(</span><span
class="s">"kerbalnaut0002"</span><span class="o">,</span> <span
class="n">OBSERVED_COL</span><span class="o">,</span> <span
class="s">"Bill"</span><span class="o">);</span>
- <span class="n">tx2</span><span class="o">.</span><span
class="na">commit</span><span class="o">();</span>
+ <span class="k">try</span> <span class="o">(</span><span
class="n">Transaction</span> <span class="n">tx2</span> <span
class="o">=</span> <span class="n">client</span><span class="o">.</span><span
class="na">newTransaction</span><span class="o">();</span>
+ <span class="n">Transaction</span> <span class="n">tx3</span> <span
class="o">=</span> <span class="n">client</span><span class="o">.</span><span
class="na">newTransaction</span><span class="o">();</span>
+ <span class="n">Transaction</span> <span class="n">tx4</span> <span
class="o">=</span> <span class="n">client</span><span class="o">.</span><span
class="na">newTransaction</span><span class="o">())</span>
+ <span class="o">{</span>
+ <span class="kt">int</span> <span class="n">f1w1</span> <span
class="o">=</span> <span class="n">Integer</span><span class="o">.</span><span
class="na">parseInt</span><span class="o">(</span><span
class="n">tx2</span><span class="o">.</span><span
class="na">withReadLock</span><span class="o">().</span><span
class="na">gets</span><span class="o">(</span><span
class="s">"kerbalnaut0001"</span><span class="o">,</span> <span
class="n">WEIGHT_COL</span><span class="o">));</span>
+ <span class="kt">int</span> <span class="n">f1w2</span> <span
class="o">=</span> <span class="n">Integer</span><span class="o">.</span><span
class="na">parseInt</span><span class="o">(</span><span
class="n">tx2</span><span class="o">.</span><span
class="na">withReadLock</span><span class="o">().</span><span
class="na">gets</span><span class="o">(</span><span
class="s">"kerbalnaut0003"</span><span class="o">,</span> <span
class="n">WEIGHT_COL</span><span class="o">));</span>
+ <span class="n">tx2</span><span class="o">.</span><span
class="na">set</span><span class="o">(</span><span
class="s">"flight0001"</span><span class="o">,</span> <span
class="n">WEIGHT_COL</span><span class="o">,</span> <span class="n">f1w1</span>
<span class="o">+</span> <span class="n">f1w2</span> <span class="o">+</span>
<span class="s">""</span><span class="o">);</span>
+
+ <span class="kt">int</span> <span class="n">f2w1</span> <span
class="o">=</span> <span class="n">Integer</span><span class="o">.</span><span
class="na">parseInt</span><span class="o">(</span><span
class="n">tx3</span><span class="o">.</span><span
class="na">withReadLock</span><span class="o">().</span><span
class="na">gets</span><span class="o">(</span><span
class="s">"kerbalnaut0001"</span><span class="o">,</span> <span
class="n">WEIGHT_COL</span><span class="o">));</span>
+ <span class="kt">int</span> <span class="n">f2w2</span> <span
class="o">=</span> <span class="n">Integer</span><span class="o">.</span><span
class="na">parseInt</span><span class="o">(</span><span
class="n">tx3</span><span class="o">.</span><span
class="na">withReadLock</span><span class="o">().</span><span
class="na">gets</span><span class="o">(</span><span
class="s">"kerbalnaut0002"</span><span class="o">,</span> <span
class="n">WEIGHT_COL</span><span class="o">));</span>
+ <span class="n">tx3</span><span class="o">.</span><span
class="na">set</span><span class="o">(</span><span
class="s">"flight0002"</span><span class="o">,</span> <span
class="n">WEIGHT_COL</span><span class="o">,</span> <span class="n">f2w1</span>
<span class="o">+</span> <span class="n">f2w2</span> <span class="o">+</span>
<span class="s">""</span><span class="o">);</span>
+
+ <span class="n">tx4</span><span class="o">.</span><span
class="na">set</span><span class="o">(</span><span
class="s">"kerbalnaut0001"</span><span class="o">,</span> <span
class="n">WEIGHT_COL</span><span class="o">,</span> <span
class="s">"95"</span><span class="o">);</span>
+
+ <span class="k">for</span><span class="o">(</span><span
class="n">Transaction</span> <span class="n">ctx</span> <span
class="o">:</span> <span class="n">Arrays</span><span class="o">.</span><span
class="na">asList</span><span class="o">(</span><span class="n">tx2</span><span
class="o">,</span><span class="n">tx3</span><span class="o">,</span><span
class="n">tx4</span><span class="o">))</span> <span class="o">{</span>
+ <span class="k">try</span> <span class="o">{</span>
+ <span class="n">ctx</span><span class="o">.</span><span
class="na">commit</span><span class="o">();</span>
+ <span class="o">}</span> <span class="k">catch</span> <span
class="o">(</span><span class="n">CommitException</span> <span
class="n">ce</span><span class="o">)</span> <span class="o">{</span>
+ <span class="n">System</span><span class="o">.</span><span
class="na">out</span><span class="o">.</span><span
class="na">println</span><span class="o">(</span><span class="s">"commit
failed: "</span><span class="o">+</span><span class="n">ce</span><span
class="o">.</span><span class="na">getMessage</span><span class="o">());</span>
+ <span class="o">}</span>
+ <span class="o">}</span>
<span class="o">}</span>
- <span class="n">mini</span><span class="o">.</span><span
class="na">waitForObservers</span><span class="o">();</span>
-
- <span class="k">try</span> <span class="o">(</span><span
class="n">Snapshot</span> <span class="n">snap</span> <span class="o">=</span>
<span class="n">client</span><span class="o">.</span><span
class="na">newSnapshot</span><span class="o">())</span> <span class="o">{</span>
+ <span class="k">try</span><span class="o">(</span><span
class="n">Snapshot</span> <span class="n">snap</span> <span class="o">=</span>
<span class="n">client</span><span class="o">.</span><span
class="na">newSnapshot</span><span class="o">())</span> <span class="o">{</span>
<span class="n">snap</span><span class="o">.</span><span
class="na">scanner</span><span class="o">().</span><span
class="na">build</span><span class="o">().</span><span
class="na">forEach</span><span class="o">(</span><span
class="n">System</span><span class="o">.</span><span class="na">out</span><span
class="o">::</span><span class="n">println</span><span class="o">);</span>
<span class="o">}</span>
<span class="o">}</span>
</code></pre></div></div>
-<p>The code above prints :</p>
+<p>Output :</p>
-<div class="highlighter-rouge"><div class="highlight"><pre
class="highlight"><code>Bill inv data kerbalnaut0002
-Jebediah inv data kerbalnaut0001
-kerbalnaut0001 obs data Jebediah
-kerbalnaut0002 obs data Bill
+<div class="highlighter-rouge"><div class="highlight"><pre
class="highlight"><code>commit failed: Collisions(1):kerbalnaut0001 stat weight
+flight0001 stat weight 170
+flight0002 stat weight 160
+kerbalnaut0001 stat weight 90
+kerbalnaut0002 stat weight 70
+kerbalnaut0003 stat weight 80
</code></pre></div></div>
-<p>The following events happen when this code is run.</p>
-
-<ul>
- <li><em>tx1</em> modifies <em>kerbalnaut0001:obs:data</em> causing
<em>MyObserver</em> to run later on that row+column.</li>
- <li><em>tx2</em> modifies <em>kerbalnaut0002:obs:data</em> causing
<em>MyObserver</em> to run later on that row+column.</li>
- <li>Later <em>MyObserver</em> is run and passed row+column
<em>kerbalnaut0001:obs:data</em></li>
- <li>Later <em>MyObserver</em> is run and passed row+column
<em>kerbalnaut0002:obs:data</em></li>
-</ul>
+<p>Output for commit order <code
class="highlighter-rouge">Arrays.asList(tx4,tx2,tx3)</code> :</p>
-<p>Observers are run in the background by Fluo threads. Fluo also creates the
-transaction passed to an Observer and commits it. The transaction does not
-need to call commit and can not, the TransactionBase type passed to an Observer
-does not have a commit method. The framework handles committing because it
-retries in case of a commit exception.</p>
-
-<p>Since observers are run in the background, you never know when they will
run.
-For testing purposes MiniFluo provides the waitForObservers() method that is
-called above. This method waits for all notifications to be processed by
-observers.</p>
-
-<p>There is no stand alone exercise for the Observer. Hands on experience
with it can be obtained by
-completing the <a href="/tour/exercise-1/">word count exercise</a> which is
the next step in the tour.</p>
+<div class="highlighter-rouge"><div class="highlight"><pre
class="highlight"><code>commit failed: Collisions(1):kerbalnaut0001 stat weight
+commit failed: Collisions(1):kerbalnaut0001 stat weight
+kerbalnaut0001 stat weight 95
+kerbalnaut0002 stat weight 70
+kerbalnaut0003 stat weight 80
+</code></pre></div></div>
+<p>With this commit order <em>tx4</em> gets a write lock on
<em>kerbalnaut0001:stat:weight</em>
+which prevents <em>tx2</em> and <em>tx3</em> from getting read locks.</p>
</div>
<script>
document.body.onkeyup = function(e){
-if (e.keyCode == '37') { window.location = '/tour/observers/'; }
+if (e.keyCode == '37') { window.location = '/tour/read-lock/'; }
-if (e.keyCode == '39') { window.location = '/tour/exercise-1/'; }
+if (e.keyCode == '39') { window.location = '/tour/scanning/'; }
};
</script>
@@ -214,12 +194,12 @@ if (e.keyCode == '39') { window.location =
'/tour/exercise-1/'; }
<h2>
- <a href="/tour/observers/"><</a>
+ <a href="/tour/read-lock/"><</a>
- 18 / 26
+ 14 / 28
- <a href="/tour/exercise-1/">></a>
+ <a href="/tour/scanning/">></a>
</h2>
</div>
diff --git a/tour/write-skew/index.html b/tour/read-lock/index.html
similarity index 76%
copy from tour/write-skew/index.html
copy to tour/read-lock/index.html
index 25a1862..4c3e93e 100644
--- a/tour/write-skew/index.html
+++ b/tour/read-lock/index.html
@@ -8,10 +8,10 @@
<link
href="https://maxcdn.bootstrapcdn.com/bootswatch/3.3.7/cosmo/bootstrap.min.css";
rel="stylesheet"
integrity="sha384-h21C2fcDk/eFsW9sC9h0dhokq5pDinLNklTKoxIZRUn3+hvmgQSffLLQ4G4l2eEr"
crossorigin="anonymous">
<link
href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css";
rel="stylesheet"
integrity="sha384-wvfXpqpZZVQGK6TAh5PVlGOfQNHSoD2xbE+QkPxCAFlNEevoEH3Sl0sibVcOQVnN"
crossorigin="anonymous">
<link rel="stylesheet" href="/css/fluo.css">
- <link rel="canonical" href="https://fluo.apache.org//tour/write-skew/";>
+ <link rel="canonical" href="https://fluo.apache.org//tour/read-lock/";>
<link rel="icon" type="image/png" href="/resources/favicon.png">
- <title>Write Skew | Apache Fluo</title>
+ <title>Read Locks | Apache Fluo</title>
<script
src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js";></script>
<script
src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js";
integrity="sha384-Tc5IQib027qvyjSMfHjOMaLkfuWVxZxUPnCJA7l2mCWNIpG9mGCD8wGNIcPD7Txa"
crossorigin="anonymous"></script>
@@ -111,49 +111,47 @@
<div id="tour-header">
- <h2><a href="/tour/">Fluo Tour</a>: Write Skew</h2>
- <p class="text-muted">Tour page 11 of 26</p>
+ <h2><a href="/tour/">Fluo Tour</a>: Read Locks</h2>
+ <p class="text-muted">Tour page 13 of 28</p>
</div>
<div id="tour-content">
- <p>The page on collisions showed that if two transactions overlap and write
the same data then one will
-fail. However, in the case where two transactions overlap and one reads data
that another is writing
-both can succeed. This behavior is called write skew.</p>
-
-<p>The example below shows write skew. In the example, <em>n0</em> is a node
in a tree with two children <em>n01</em>
-and <em>n02</em>. In <em>tx2</em>, the sum of <em>n0</em> is set to the sum
of its children. However, <em>tx2</em> misses the
-concurrent update from <em>tx3</em>. Both <em>tx2</em> and <em>tx3</em> will
commit successfully since they write to
-different keys.</p>
+ <p>By default, reads do not acquire a lock which makes normal reads faster.
+Read locks can optionally be acquired via the <a
href="https://javadoc.io/page/org.apache.fluo/fluo-api/1.2.0/org/apache/fluo/api/client/TransactionBase.html#withReadLock--";>withReadLock</a>
method. For
+example, if <code class="highlighter-rouge">tx</code> is a transaction then
<code class="highlighter-rouge">tx.withReadLock().get(row,col)</code>
+reads with a lock.</p>
<ul>
<li><strong>Create transaction</strong> <em>tx1</em></li>
- <li><strong>Using</strong> <em>tx1</em> <strong>set</strong>
<em>n0:data:sum</em> <strong>to</strong> <em>0</em></li>
- <li><strong>Using</strong> <em>tx1</em> <strong>set</strong>
<em>n01:data:sum</em> <strong>to</strong> <em>1</em></li>
- <li><strong>Using</strong> <em>tx1</em> <strong>set</strong>
<em>n02:data:sum</em> <strong>to</strong> <em>2</em></li>
+ <li><strong>Using</strong> <em>tx1</em> <strong>set</strong>
<em>kerbalnaut0001:stat:weight</em> <strong>to</strong> <em>90</em></li>
+ <li><strong>Using</strong> <em>tx1</em> <strong>set</strong>
<em>kerbalnaut0002:stat:weight</em> <strong>to</strong> <em>70</em></li>
+ <li><strong>Using</strong> <em>tx1</em> <strong>set</strong>
<em>kerbalnaut0003:stat:weight</em> <strong>to</strong> <em>80</em></li>
<li><strong>Commit</strong> <em>tx1</em></li>
<li><strong>Create transaction</strong> <em>tx2</em></li>
<li><strong>Create transaction</strong> <em>tx3</em></li>
- <li><strong>Using</strong> <em>tx2</em> <strong>set</strong>
<em>n0:data:sum</em> <strong>to the value of</strong> <em>n01:data:sum</em>
<strong>plus</strong> <em>n02:data:sum</em></li>
- <li><strong>Using</strong> <em>tx3</em> <strong>set</strong>
<em>n01:data:sum</em> <strong>to</strong> <em>5</em></li>
+ <li><strong>Create transaction</strong> <em>tx4</em></li>
+ <li><strong>Using</strong> <em>tx2</em> <strong>set</strong>
<em>flight0001:stat:weight</em> <strong>to the read locked values of</strong>
<em>kerbalnaut0001:stat:weight</em> <strong>plus</strong>
<em>kerbalnaut0003:stat:weight</em></li>
+ <li><strong>Using</strong> <em>tx3</em> <strong>set</strong>
<em>flight0002:stat:weight</em> <strong>to the read locked values of</strong>
<em>kerbalnaut0001:stat:weight</em> <strong>plus</strong>
<em>kerbalnaut0002:stat:weight</em></li>
+ <li><strong>Using</strong> <em>tx4</em> <strong>set</strong>
<em>kerbalnaut0001:stat:weight</em> <strong>to</strong> <em>95</em></li>
<li><strong>Commit</strong> <em>tx2</em></li>
<li><strong>Commit</strong> <em>tx3</em></li>
- <li><strong>Create snapshot and print</strong> <em>n0:data:sum</em>,
<em>n01:data:sum</em>, <strong>and</strong> <em>n02:data:sum</em></li>
+ <li><strong>Commit</strong> <em>tx4</em></li>
</ul>
-<p>The changes made by <em>tx3</em> will not be seen by <em>tx2</em>. This
behavior is OK if the update made by <em>tx3</em>
-triggers a later update of <em>n0:data:sum</em>. Later pages in the tour will
show that Observers can work
-this way, so that eventually the changes made by <em>tx3</em> are
incorporated. The <a href="/tour/weak-notifications/">Weak Notification
-Exercise</a> later in the tour shows an example of this.</p>
+<p>Both <em>tx2</em> and <em>tx3</em> get a read lock on
<em>kerbalnaut0001:stat:weight</em> without
+interfering with each other. The read locks prevent <em>tx4</em> from
committing.
+Try reordering the commits for <em>tx2</em>, <em>tx3</em>, and
<em>tx4</em>.</p>
+
</div>
<script>
document.body.onkeyup = function(e){
-if (e.keyCode == '37') { window.location = '/tour/tx-logging/'; }
+if (e.keyCode == '37') { window.location = '/tour/write-skew-code/'; }
-if (e.keyCode == '39') { window.location = '/tour/write-skew-code/'; }
+if (e.keyCode == '39') { window.location = '/tour/read-lock-code/'; }
};
</script>
@@ -162,12 +160,12 @@ if (e.keyCode == '39') { window.location =
'/tour/write-skew-code/'; }
<h2>
- <a href="/tour/tx-logging/"><</a>
+ <a href="/tour/write-skew-code/"><</a>
- 11 / 26
+ 13 / 28
- <a href="/tour/write-skew-code/">></a>
+ <a href="/tour/read-lock-code/">></a>
</h2>
</div>
diff --git a/tour/recipes/index.html b/tour/recipes/index.html
index 22264da..a970d6e 100644
--- a/tour/recipes/index.html
+++ b/tour/recipes/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Fluo Recipes</h2>
- <p class="text-muted">Tour page 26 of 26</p>
+ <p class="text-muted">Tour page 28 of 28</p>
</div>
<div id="tour-content">
<p>Coming soon, a tour of <a
href="https://github.com/apache/fluo-recipes";>Fluo Recipes</a>.</p>
@@ -137,7 +137,7 @@ if (e.keyCode == '37') { window.location =
'/tour/mem-self-ntfy-code/'; }
<a href="/tour/mem-self-ntfy-code/"><</a>
- 26 / 26
+ 28 / 28
</h2>
</div>
diff --git a/tour/row-locking/index.html b/tour/row-locking/index.html
index 0f4c4e0..b0dad38 100644
--- a/tour/row-locking/index.html
+++ b/tour/row-locking/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Row Locking</h2>
- <p class="text-muted">Tour page 20 of 26</p>
+ <p class="text-muted">Tour page 22 of 28</p>
</div>
<div id="tour-content">
<p>Fluo relies on Accumulo’s conditional mutations to implement cross node
@@ -233,7 +233,7 @@ if (e.keyCode == '39') { window.location =
'/tour/weak-notifications/'; }
<a href="/tour/exercise-1/"><</a>
- 20 / 26
+ 22 / 28
<a href="/tour/weak-notifications/">></a>
diff --git a/tour/scanning-code/index.html b/tour/scanning-code/index.html
index 195435e..681a57d 100644
--- a/tour/scanning-code/index.html
+++ b/tour/scanning-code/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Scanning Code</h2>
- <p class="text-muted">Tour page 14 of 26</p>
+ <p class="text-muted">Tour page 16 of 28</p>
</div>
<div id="tour-content">
<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code> <span class="kd">private</span> <span
class="kd">static</span> <span class="kt">void</span> <span
class="nf">exercise</span><span class="o">(</span><span
class="n">MiniFluo</span> <span class="n">mini</span><span class="o">,</span>
<span class="n">FluoClient</span> <span class="n">client</span><span
class="o">)</span> <span class="o">{</span>
@@ -205,7 +205,7 @@ if (e.keyCode == '39') { window.location =
'/tour/multi-get/'; }
<a href="/tour/scanning/"><</a>
- 14 / 26
+ 16 / 28
<a href="/tour/multi-get/">></a>
diff --git a/tour/scanning/index.html b/tour/scanning/index.html
index a8cacbb..9778f55 100644
--- a/tour/scanning/index.html
+++ b/tour/scanning/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Scanning</h2>
- <p class="text-muted">Tour page 13 of 26</p>
+ <p class="text-muted">Tour page 15 of 28</p>
</div>
<div id="tour-content">
<p>In some situations, you may want to read a range of data instead of
specific rows and columns. For
@@ -153,7 +153,7 @@ change data after <em>s1</em> is created but before the
scans happen.</p>
<script>
document.body.onkeyup = function(e){
-if (e.keyCode == '37') { window.location = '/tour/write-skew-code/'; }
+if (e.keyCode == '37') { window.location = '/tour/read-lock-code/'; }
@@ -166,10 +166,10 @@ if (e.keyCode == '39') { window.location =
'/tour/scanning-code/'; }
<h2>
- <a href="/tour/write-skew-code/"><</a>
+ <a href="/tour/read-lock-code/"><</a>
- 13 / 26
+ 15 / 28
<a href="/tour/scanning-code/">></a>
diff --git a/tour/snapshot-isolation-code/index.html
b/tour/snapshot-isolation-code/index.html
index 0d38e85..7f8efa4 100644
--- a/tour/snapshot-isolation-code/index.html
+++ b/tour/snapshot-isolation-code/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Snapshot Isolation Code</h2>
- <p class="text-muted">Tour page 7 of 26</p>
+ <p class="text-muted">Tour page 7 of 28</p>
</div>
<div id="tour-content">
<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code> <span class="kd">private</span> <span
class="kd">static</span> <span class="kt">void</span> <span
class="nf">exercise</span><span class="o">(</span><span
class="n">MiniFluo</span> <span class="n">mini</span><span class="o">,</span>
<span class="n">FluoClient</span> <span class="n">client</span><span
class="o">)</span> <span class="o">{</span>
@@ -171,7 +171,7 @@ if (e.keyCode == '39') { window.location =
'/tour/collisions/'; }
<a href="/tour/snapshot-isolation/"><</a>
- 7 / 26
+ 7 / 28
<a href="/tour/collisions/">></a>
diff --git a/tour/snapshot-isolation/index.html
b/tour/snapshot-isolation/index.html
index bc432b8..4979d44 100644
--- a/tour/snapshot-isolation/index.html
+++ b/tour/snapshot-isolation/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Snapshot Isolation</h2>
- <p class="text-muted">Tour page 6 of 26</p>
+ <p class="text-muted">Tour page 6 of 28</p>
</div>
<div id="tour-content">
<p>Fluo provides Snapshot isolation. This means that a Transaction or
Snapshot can only see data
@@ -154,7 +154,7 @@ if (e.keyCode == '39') { window.location =
'/tour/snapshot-isolation-code/'; }
<a href="/tour/data-pojos/"><</a>
- 6 / 26
+ 6 / 28
<a href="/tour/snapshot-isolation-code/">></a>
diff --git a/tour/tx-logging/index.html b/tour/tx-logging/index.html
index 7d5ba5f..0b2e7c7 100644
--- a/tour/tx-logging/index.html
+++ b/tour/tx-logging/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Transaction Logging</h2>
- <p class="text-muted">Tour page 10 of 26</p>
+ <p class="text-muted">Tour page 10 of 28</p>
</div>
<div id="tour-content">
<p>Fluo can produce detailed logs about transactions if configured to do so.
@@ -174,7 +174,7 @@ if (e.keyCode == '39') { window.location =
'/tour/write-skew/'; }
<a href="/tour/collision-code/"><</a>
- 10 / 26
+ 10 / 28
<a href="/tour/write-skew/">></a>
diff --git a/tour/weak-code/index.html b/tour/weak-code/index.html
index 4869ebe..514c74e 100644
--- a/tour/weak-code/index.html
+++ b/tour/weak-code/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Weak Notification Code</h2>
- <p class="text-muted">Tour page 22 of 26</p>
+ <p class="text-muted">Tour page 24 of 28</p>
</div>
<div id="tour-content">
<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code> <span class="kd">static</span> <span
class="n">Column</span> <span class="n">NC</span> <span class="o">=</span>
<span class="k">new</span> <span class="n">Column</span><span
class="o">(</span><span class="s">"ntyf"</span><span class="o">,</span> <span
class="s">"sum"</span><span class="o">);</span>
@@ -204,7 +204,7 @@ if (e.keyCode == '39') { window.location =
'/tour/application-configuration/'; }
<a href="/tour/weak-notifications/"><</a>
- 22 / 26
+ 24 / 28
<a href="/tour/application-configuration/">></a>
diff --git a/tour/weak-notifications/index.html
b/tour/weak-notifications/index.html
index e965ee3..4093cfa 100644
--- a/tour/weak-notifications/index.html
+++ b/tour/weak-notifications/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Weak Notification Exercise</h2>
- <p class="text-muted">Tour page 21 of 26</p>
+ <p class="text-muted">Tour page 23 of 28</p>
</div>
<div id="tour-content">
<p>This exercise will use weak notification to update a shared counter. In
the example, many threads
@@ -163,7 +163,7 @@ if (e.keyCode == '39') { window.location =
'/tour/weak-code/'; }
<a href="/tour/row-locking/"><</a>
- 21 / 26
+ 23 / 28
<a href="/tour/weak-code/">></a>
diff --git a/tour/write-skew-code/index.html b/tour/write-skew-code/index.html
index 024acdc..0f61401 100644
--- a/tour/write-skew-code/index.html
+++ b/tour/write-skew-code/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Write Skew Code</h2>
- <p class="text-muted">Tour page 12 of 26</p>
+ <p class="text-muted">Tour page 12 of 28</p>
</div>
<div id="tour-content">
<div class="language-java highlighter-rouge"><div class="highlight"><pre
class="highlight"><code> <span class="kd">private</span> <span
class="kd">static</span> <span class="kt">void</span> <span
class="nf">exercise</span><span class="o">(</span><span
class="n">MiniFluo</span> <span class="n">mini</span><span class="o">,</span>
<span class="n">FluoClient</span> <span class="n">client</span><span
class="o">)</span> <span class="o">{</span>
@@ -163,7 +163,7 @@ if (e.keyCode == '37') { window.location =
'/tour/write-skew/'; }
-if (e.keyCode == '39') { window.location = '/tour/scanning/'; }
+if (e.keyCode == '39') { window.location = '/tour/read-lock/'; }
};
</script>
@@ -175,9 +175,9 @@ if (e.keyCode == '39') { window.location =
'/tour/scanning/'; }
<a href="/tour/write-skew/"><</a>
- 12 / 26
+ 12 / 28
- <a href="/tour/scanning/">></a>
+ <a href="/tour/read-lock/">></a>
</h2>
</div>
diff --git a/tour/write-skew/index.html b/tour/write-skew/index.html
index 25a1862..3fd1400 100644
--- a/tour/write-skew/index.html
+++ b/tour/write-skew/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Write Skew</h2>
- <p class="text-muted">Tour page 11 of 26</p>
+ <p class="text-muted">Tour page 11 of 28</p>
</div>
<div id="tour-content">
<p>The page on collisions showed that if two transactions overlap and write
the same data then one will
@@ -142,7 +142,8 @@ different keys.</p>
<p>The changes made by <em>tx3</em> will not be seen by <em>tx2</em>. This
behavior is OK if the update made by <em>tx3</em>
triggers a later update of <em>n0:data:sum</em>. Later pages in the tour will
show that Observers can work
this way, so that eventually the changes made by <em>tx3</em> are
incorporated. The <a href="/tour/weak-notifications/">Weak Notification
-Exercise</a> later in the tour shows an example of this.</p>
+Exercise</a> later in the tour shows an example of this. Another strategy
+for dealing with write skew is <a href="/tour/read-lock/">read locks</a>.</p>
</div>
@@ -165,7 +166,7 @@ if (e.keyCode == '39') { window.location =
'/tour/write-skew-code/'; }
<a href="/tour/tx-logging/"><</a>
- 11 / 26
+ 11 / 28
<a href="/tour/write-skew-code/">></a>
diff --git a/tour/writing-code/index.html b/tour/writing-code/index.html
index bd07768..af8f5b0 100644
--- a/tour/writing-code/index.html
+++ b/tour/writing-code/index.html
@@ -112,7 +112,7 @@
<div id="tour-header">
<h2><a href="/tour/">Fluo Tour</a>: Writing and Running Fluo code</h2>
- <p class="text-muted">Tour page 3 of 26</p>
+ <p class="text-muted">Tour page 3 of 28</p>
</div>
<div id="tour-content">
<p>Following the Fluo tour will require writing code that uses Fluo’s API.
There is a git repository
@@ -155,7 +155,7 @@ if (e.keyCode == '39') { window.location =
'/tour/basic-read-write/'; }
<a href="/tour/architecture/"><</a>
- 3 / 26
+ 3 / 28
<a href="/tour/basic-read-write/">></a>
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