├── .gitignore ├── LICENSE ├── README.md └── src ├── AzureSQLTransientHandling.sln └── AzureSQLTransientHandling ├── AzureSQLTransientHandling.csproj ├── Customer.cs ├── PollySqlExtensions.cs └── Program.cs /.gitignore: -------------------------------------------------------------------------------- 1 | ## Ignore Visual Studio temporary files, build results, and 2 | ## files generated by popular Visual Studio add-ons. 3 | 4 | # User-specific files 5 | *.suo 6 | *.user 7 | *.userosscache 8 | *.sln.docstates 9 | 10 | # User-specific files (MonoDevelop/Xamarin Studio) 11 | *.userprefs 12 | 13 | # Build results 14 | [Dd]ebug/ 15 | [Dd]ebugPublic/ 16 | [Rr]elease/ 17 | [Rr]eleases/ 18 | x64/ 19 | x86/ 20 | bld/ 21 | [Bb]in/ 22 | [Oo]bj/ 23 | [Ll]og/ 24 | 25 | # Visual Studio 2015 cache/options directory 26 | .vs/ 27 | # Uncomment if you have tasks that create the project's static files in wwwroot 28 | #wwwroot/ 29 | 30 | # MSTest test Results 31 | [Tt]est[Rr]esult*/ 32 | [Bb]uild[Ll]og.* 33 | 34 | # NUNIT 35 | *.VisualState.xml 36 | TestResult.xml 37 | 38 | # Build Results of an ATL Project 39 | [Dd]ebugPS/ 40 | [Rr]eleasePS/ 41 | dlldata.c 42 | 43 | # DNX 44 | project.lock.json 45 | artifacts/ 46 | 47 | *_i.c 48 | *_p.c 49 | *_i.h 50 | *.ilk 51 | *.meta 52 | *.obj 53 | *.pch 54 | *.pdb 55 | *.pgc 56 | *.pgd 57 | *.rsp 58 | *.sbr 59 | *.tlb 60 | *.tli 61 | *.tlh 62 | *.tmp 63 | *.tmp_proj 64 | *.log 65 | *.vspscc 66 | *.vssscc 67 | .builds 68 | *.pidb 69 | *.svclog 70 | *.scc 71 | 72 | # Chutzpah Test files 73 | _Chutzpah* 74 | 75 | # Visual C++ cache files 76 | ipch/ 77 | *.aps 78 | *.ncb 79 | *.opendb 80 | *.opensdf 81 | *.sdf 82 | *.cachefile 83 | *.VC.db 84 | *.VC.VC.opendb 85 | 86 | # Visual Studio profiler 87 | *.psess 88 | *.vsp 89 | *.vspx 90 | *.sap 91 | 92 | # TFS 2012 Local Workspace 93 | $tf/ 94 | 95 | # Guidance Automation Toolkit 96 | *.gpState 97 | 98 | # ReSharper is a .NET coding add-in 99 | _ReSharper*/ 100 | *.[Rr]e[Ss]harper 101 | *.DotSettings.user 102 | 103 | # JustCode is a .NET coding add-in 104 | .JustCode 105 | 106 | # TeamCity is a build add-in 107 | _TeamCity* 108 | 109 | # DotCover is a Code Coverage Tool 110 | *.dotCover 111 | 112 | # NCrunch 113 | _NCrunch_* 114 | .*crunch*.local.xml 115 | nCrunchTemp_* 116 | 117 | # MightyMoose 118 | *.mm.* 119 | AutoTest.Net/ 120 | 121 | # Web workbench (sass) 122 | .sass-cache/ 123 | 124 | # Installshield output folder 125 | [Ee]xpress/ 126 | 127 | # DocProject is a documentation generator add-in 128 | DocProject/buildhelp/ 129 | DocProject/Help/*.HxT 130 | DocProject/Help/*.HxC 131 | DocProject/Help/*.hhc 132 | DocProject/Help/*.hhk 133 | DocProject/Help/*.hhp 134 | DocProject/Help/Html2 135 | DocProject/Help/html 136 | 137 | # Click-Once directory 138 | publish/ 139 | 140 | # Publish Web Output 141 | *.[Pp]ublish.xml 142 | *.azurePubxml 143 | # TODO: Comment the next line if you want to checkin your web deploy settings 144 | # but database connection strings (with potential passwords) will be unencrypted 145 | *.pubxml 146 | *.publishproj 147 | 148 | # Microsoft Azure Web App publish settings. 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Backup files are not needed, 205 | # because we have git ;-) 206 | _UpgradeReport_Files/ 207 | Backup*/ 208 | UpgradeLog*.XML 209 | UpgradeLog*.htm 210 | 211 | # SQL Server files 212 | *.mdf 213 | *.ldf 214 | 215 | # Business Intelligence projects 216 | *.rdl.data 217 | *.bim.layout 218 | *.bim_*.settings 219 | 220 | # Microsoft Fakes 221 | FakesAssemblies/ 222 | 223 | # GhostDoc plugin setting file 224 | *.GhostDoc.xml 225 | 226 | # Node.js Tools for Visual Studio 227 | .ntvs_analysis.dat 228 | 229 | # Visual Studio 6 build log 230 | *.plg 231 | 232 | # Visual Studio 6 workspace options file 233 | *.opt 234 | 235 | # Visual Studio LightSwitch build output 236 | **/*.HTMLClient/GeneratedArtifacts 237 | **/*.DesktopClient/GeneratedArtifacts 238 | **/*.DesktopClient/ModelManifest.xml 239 | **/*.Server/GeneratedArtifacts 240 | **/*.Server/ModelManifest.xml 241 | _Pvt_Extensions 242 | 243 | # Paket dependency manager 244 | .paket/paket.exe 245 | paket-files/ 246 | 247 | # FAKE - F# Make 248 | .fake/ 249 | 250 | # JetBrains Rider 251 | .idea/ 252 | *.sln.iml 253 | 254 | # Cake / Deploy 255 | [Tt]ools/ 256 | [Ll]ocal[Dd]eploy/ 257 | [Oo]utput/ -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | MIT License 2 | 3 | Copyright (c) 2017 Mattias Karlsson 4 | 5 | Permission is hereby granted, free of charge, to any person obtaining a copy 6 | of this software and associated documentation files (the "Software"), to deal 7 | in the Software without restriction, including without limitation the rights 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 9 | copies of the Software, and to permit persons to whom the Software is 10 | furnished to do so, subject to the following conditions: 11 | 12 | The above copyright notice and this permission notice shall be included in all 13 | copies or substantial portions of the Software. 14 | 15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 21 | SOFTWARE. -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Azure SQL transient errors 2 | 3 | This repository contains sample code for an upcoming [medium.com/@devlead](https://medium.com/@devlead) blog post. 4 | -------------------------------------------------------------------------------- /src/AzureSQLTransientHandling.sln: -------------------------------------------------------------------------------- 1 |  2 | Microsoft Visual Studio Solution File, Format Version 12.00 3 | # Visual Studio 15 4 | VisualStudioVersion = 15.0.26228.9 5 | MinimumVisualStudioVersion = 10.0.40219.1 6 | Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "AzureSQLTransientHandling", "AzureSQLTransientHandling\AzureSQLTransientHandling.csproj", "{66583029-9CA1-4239-B736-43C277BEE579}" 7 | EndProject 8 | Global 9 | GlobalSection(SolutionConfigurationPlatforms) = preSolution 10 | Debug|Any CPU = Debug|Any CPU 11 | Release|Any CPU = Release|Any CPU 12 | EndGlobalSection 13 | GlobalSection(ProjectConfigurationPlatforms) = postSolution 14 | {66583029-9CA1-4239-B736-43C277BEE579}.Debug|Any CPU.ActiveCfg = Debug|Any CPU 15 | {66583029-9CA1-4239-B736-43C277BEE579}.Debug|Any CPU.Build.0 = Debug|Any CPU 16 | {66583029-9CA1-4239-B736-43C277BEE579}.Release|Any CPU.ActiveCfg = Release|Any CPU 17 | {66583029-9CA1-4239-B736-43C277BEE579}.Release|Any CPU.Build.0 = Release|Any CPU 18 | EndGlobalSection 19 | GlobalSection(SolutionProperties) = preSolution 20 | HideSolutionNode = FALSE 21 | EndGlobalSection 22 | EndGlobal 23 | -------------------------------------------------------------------------------- /src/AzureSQLTransientHandling/AzureSQLTransientHandling.csproj: -------------------------------------------------------------------------------- 1 |  2 | 3 | 4 | Exe 5 | netcoreapp1.1 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | -------------------------------------------------------------------------------- /src/AzureSQLTransientHandling/Customer.cs: -------------------------------------------------------------------------------- 1 | namespace AzureSQLTransientHandling 2 | { 3 | public class Customer 4 | { 5 | public int CustomerID { get; set; } 6 | public string FirstName { get; set; } 7 | public string LastName { get; set; } 8 | public string CompanyName { get; set; } 9 | public string EmailAddress { get; set; } 10 | public string SalesPerson { get; set; } 11 | } 12 | } -------------------------------------------------------------------------------- /src/AzureSQLTransientHandling/PollySqlExtensions.cs: -------------------------------------------------------------------------------- 1 | using Polly; 2 | using System; 3 | using System.Data.SqlClient; 4 | using System.Linq; 5 | using System.Threading.Tasks; 6 | 7 | namespace AzureSQLTransientHandling 8 | { 9 | public static class PollySqlExtensions 10 | { 11 | private const int SqlRetryCount = 4; 12 | 13 | private const int SqlErrorInstanceDoesNotSupportEncryption = 20; 14 | private const int SqlErrorConnectedButLoginFailed = 64; 15 | private const int SqlErrorUnableToEstablishConnection = 233; 16 | private const int SqlErrorTransportLevelErrorReceivingResult = 10053; 17 | private const int SqlErrorTransportLevelErrorWhenSendingRequestToServer = 10054; 18 | private const int SqlErrorNetworkReleatedErrorDuringConnect = 10060; 19 | private const int SqlErrorDatabaseLimitReached = 10928; 20 | private const int SqlErrorResourceLimitReached = 10929; 21 | private const int SqlErrorServiceErrorEncountered = 40197; 22 | private const int SqlErrorServiceBusy = 40501; 23 | private const int SqlErrorServiceRequestProcessFail = 40540; 24 | private const int SqlErrorServiceExperiencingAProblem = 40545; 25 | private const int SqlErrorDatabaseUnavailable = 40613; 26 | private const int SqlErrorOperationInProgress = 40627; 27 | 28 | private static readonly Policy SqlRetryPolicy = Policy 29 | .Handle() 30 | .Or(AnyRetryableError) 31 | .WaitAndRetry(SqlRetryCount, ExponentialBackoff); 32 | 33 | private static readonly AsyncRetryPolicy SqlRetryAsyncPolicy = Policy 34 | .Handle() 35 | .Or(AnyRetryableError) 36 | .WaitAndRetryAsync(SqlRetryCount, ExponentialBackoff); 37 | 38 | private static TimeSpan ExponentialBackoff(int attempt) 39 | { 40 | return TimeSpan.FromSeconds(Math.Pow(2, attempt)); 41 | } 42 | 43 | private static bool AnyRetryableError(SqlException exception) 44 | { 45 | return exception.Errors.OfType().Any(RetryableError); 46 | } 47 | 48 | private static bool RetryableError(SqlError error) 49 | { 50 | switch (error.Number) 51 | { 52 | case SqlErrorOperationInProgress: 53 | case SqlErrorDatabaseUnavailable: 54 | case SqlErrorServiceExperiencingAProblem: 55 | case SqlErrorServiceRequestProcessFail: 56 | case SqlErrorServiceBusy: 57 | case SqlErrorServiceErrorEncountered: 58 | case SqlErrorResourceLimitReached: 59 | case SqlErrorDatabaseLimitReached: 60 | case SqlErrorNetworkReleatedErrorDuringConnect: 61 | case SqlErrorTransportLevelErrorWhenSendingRequestToServer: 62 | case SqlErrorTransportLevelErrorReceivingResult: 63 | case SqlErrorUnableToEstablishConnection: 64 | case SqlErrorConnectedButLoginFailed: 65 | case SqlErrorInstanceDoesNotSupportEncryption: 66 | return true; 67 | 68 | default: 69 | return false; 70 | } 71 | } 72 | 73 | public static SqlConnection OpenWithRetry(this SqlConnection conn) 74 | { 75 | SqlRetryPolicy.Execute(conn.Open); 76 | return conn; 77 | } 78 | 79 | public static async Task OpenWithRetryAsync(this SqlConnection conn) 80 | { 81 | await SqlRetryAsyncPolicy.ExecuteAsync(conn.OpenAsync); 82 | return conn; 83 | } 84 | 85 | public static TResult OpenWithRetry(this SqlConnection conn, Func process) 86 | { 87 | return SqlRetryPolicy.Execute(() => 88 | { 89 | conn.Open(); 90 | return process(conn); 91 | } 92 | ); 93 | } 94 | 95 | public static Task OpenWithRetryAsync(this SqlConnection conn, Func> process) 96 | { 97 | return SqlRetryAsyncPolicy.ExecuteAsync(async () => 98 | { 99 | await conn.OpenAsync(); 100 | return await process(conn); 101 | } 102 | ); 103 | } 104 | } 105 | } -------------------------------------------------------------------------------- /src/AzureSQLTransientHandling/Program.cs: -------------------------------------------------------------------------------- 1 | using Dapper; 2 | using System; 3 | using System.Data.SqlClient; 4 | using System.Linq; 5 | using System.Threading.Tasks; 6 | 7 | namespace AzureSQLTransientHandling 8 | { 9 | class Program 10 | { 11 | private static readonly string SampleDBConnectionString = Environment.GetEnvironmentVariable("SQLAZURECONNSTR_WCOMSAMPLE"); 12 | 13 | static void Main(string[] args) 14 | { 15 | Demo().Wait(); 16 | } 17 | 18 | private static async Task Demo() 19 | { 20 | using (var connection = new SqlConnection(SampleDBConnectionString)) 21 | { 22 | connection.OpenWithRetry(); 23 | } 24 | 25 | using (var connection = new SqlConnection(SampleDBConnectionString)) 26 | { 27 | await connection.OpenWithRetryAsync(); 28 | } 29 | 30 | using (var connection = new SqlConnection(SampleDBConnectionString)) 31 | { 32 | var customer = connection 33 | .OpenWithRetry() 34 | .Query(SelectCustomerStatement, new { CustomerId = 1}) 35 | .FirstOrDefault(); 36 | } 37 | 38 | using (var connection = new SqlConnection(SampleDBConnectionString)) 39 | { 40 | var customer = connection 41 | .OpenWithRetry( 42 | conn=>conn.Query( 43 | SelectCustomerStatement, new { CustomerId = 1 }) 44 | ).FirstOrDefault(); 45 | } 46 | 47 | using (var connection = new SqlConnection(SampleDBConnectionString)) 48 | { 49 | await connection.OpenWithRetryAsync(); 50 | var customer = (await connection.QueryAsync( 51 | SelectCustomerStatement, 52 | new { CustomerId = 1 } 53 | ) 54 | ).FirstOrDefault(); 55 | } 56 | } 57 | 58 | private const string SelectCustomerStatement = @" 59 | SELECT CustomerID, 60 | FirstName, 61 | LastName, 62 | CompanyName, 63 | EmailAddress, 64 | SalesPerson 65 | FROM [SalesLT].[Customer] 66 | WHERE CustomerID = @CustomerID"; 67 | } 68 | } --------------------------------------------------------------------------------