Add Retry Support

ballerina/Dependencies.toml

@@ -5,12 +5,12 @@
 
 [ballerina]
 dependencies-toml-version = "2"
-distribution-version = "2201.12.0"
+distribution-version = "2201.13.0"
 
 [[package]]
 org = "ballerina"
 name = "crypto"
-version = "2.10.0"
+version = "2.10.1"
 dependencies = [
 	{org = "ballerina", name = "jballerina.java"},
 	{org = "ballerina", name = "time"}
@@ -46,7 +46,7 @@ modules = [
 [[package]]
 org = "ballerina"
 name = "data.xmldata"
-version = "1.5.2"
+version = "1.5.3"
 dependencies = [
 	{org = "ballerina", name = "jballerina.java"},
 	{org = "ballerina", name = "lang.object"}
@@ -58,7 +58,7 @@ modules = [
 [[package]]
 org = "ballerina"
 name = "file"
-version = "1.11.0"
+version = "1.12.0"
 scope = "testOnly"
 dependencies = [
 	{org = "ballerina", name = "io"},
@@ -201,7 +201,7 @@ dependencies = [
 [[package]]
 org = "ballerina"
 name = "log"
-version = "2.14.0"
+version = "2.16.1"
 dependencies = [
 	{org = "ballerina", name = "io"},
 	{org = "ballerina", name = "jballerina.java"},
@@ -215,15 +215,15 @@ modules = [
 [[package]]
 org = "ballerina"
 name = "observe"
-version = "1.5.0"
+version = "1.7.0"
 dependencies = [
 	{org = "ballerina", name = "jballerina.java"}
 ]
 
 [[package]]
 org = "ballerina"
 name = "os"
-version = "1.10.0"
+version = "1.10.1"
 scope = "testOnly"
 dependencies = [
 	{org = "ballerina", name = "io"},
@@ -233,7 +233,7 @@ dependencies = [
 [[package]]
 org = "ballerina"
 name = "task"
-version = "2.11.0"
+version = "2.11.1"
 dependencies = [
 	{org = "ballerina", name = "jballerina.java"},
 	{org = "ballerina", name = "time"},

ballerina/client_endpoint.bal

@@ -450,8 +450,9 @@ public enum Compression {
 # + sftpCompression - Compression algorithms (SFTP only)
 # + sftpSshKnownHosts - Path to SSH known_hosts file (SFTP only)
 # + proxy - Proxy configuration for SFTP connections (SFTP only)
-# + csvFailSafe - Configuration for fail-safe CSV content processing. In the fail-safe mode, 
+# + csvFailSafe - Configuration for fail-safe CSV content processing. In the fail-safe mode,
 #                 malformed CSV records are skipped and written to a separate file in the current directory
+# + retryConfig - Configuration for retry behavior on transient failures. If not specified, no retry is attempted.
 public type ClientConfiguration record {|
     Protocol protocol = FTP;
     string host = "127.0.0.1";
@@ -466,6 +467,7 @@ public type ClientConfiguration record {|
     TransferCompression[] sftpCompression = [NO];
     string sftpSshKnownHosts?;
     FailSafeOptions csvFailSafe?;
+    RetryConfig retryConfig?;
 |};
 
 isolated function getInputContent(string path, stream<byte[] & readonly, io:Error?>|string|xml|json content,

ballerina/commons.bal

@@ -178,6 +178,20 @@ public type SocketConfig record {|
     decimal sftpSessionTimeout = 300.0;
 |};
 
+# Configuration for retry behavior on transient failures.
+# Enables automatic retry with exponential backoff for read operations.
+#
+# + count - Maximum number of retry attempts (default: 3)
+# + interval - Initial wait time in seconds between retries (default: 1.0)
+# + backOffFactor - Multiplier for exponential backoff (default: 2.0)
+# + maxWaitInterval - Maximum wait time cap in seconds (default: 30.0)
+public type RetryConfig record {|
+    int count = 3;
+    decimal interval = 1.0;
+    float backOffFactor = 2.0;
+    decimal maxWaitInterval = 30.0;
+|};
+
 # Internal configuration for content to be written in put and append operations.
 #
 # + filePath - Path of the file to be created or appended

ballerina/error.bal

@@ -16,3 +16,27 @@
 
 # Defines the common error type for the module.
 public type Error distinct error;
+
+# Represents an error that occurs when connecting to the FTP/SFTP server.
+# This includes network failures, host unreachable, connection refused, etc.
+public type ConnectionError distinct Error;
+
+# Represents an error that occurs when a requested file or directory is not found.
+public type FileNotFoundError distinct Error;
+
+# Represents an error that occurs when attempting to create a file or directory that already exists.
+public type FileAlreadyExistsError distinct Error;
+
+# Represents an error that occurs when FTP/SFTP configuration is invalid.
+# This includes invalid port numbers, invalid regex patterns, invalid timeout values, etc.
+public type InvalidConfigurationError distinct Error;
+
+# Represents an error that occurs when the FTP/SFTP service is temporarily unavailable.
+# This is a transient error indicating the operation may succeed on retry.
+# Common causes include: server overload (421), connection issues (425, 426),
+# temporary file locks (450), or server-side processing errors (451).
+public type ServiceUnavailableError distinct Error;
+
+# Represents an error that occurs when all retry attempts have been exhausted.
+# This error wraps the last failure encountered during retry attempts.
+public type AllRetryAttemptsFailedError distinct Error;

ballerina/tests/advanced_file_selection_test.bal

@@ -65,7 +65,7 @@ function testFileAgeFilterRespectsMaxAge() returns error? {
             }
         },
         path: "/home/in/advanced/age",
-        pollingInterval: 5,
+        pollingInterval: 2,
         fileAgeFilter: {
             maxAge: 60
         },